bpo-29591: Upgrade Modules/expat to libexpat 2.2 (#2164)

* bpo-29591: Upgrade Modules/expat to libexpat 2.2

* bpo-29591: Restore Python changes on expat

* bpo-29591: Remove expat config of unsupported platforms

Remove the configuration (Modules/expat/*config.h) of unsupported
platforms:

* Amiga
* MacOS Classic on PPC32
* Open Watcom

* bpo-29591: Remove useless XML_HAS_SET_HASH_SALT

The XML_HAS_SET_HASH_SALT define of Modules/expat/expat.h became
useless since our local expat copy was upgrade to expat 2.1 (it's now
expat 2.2.0).
diff --git a/Modules/expat/xmlrole.c b/Modules/expat/xmlrole.c
index 44772e2..fcd0dc6 100644
--- a/Modules/expat/xmlrole.c
+++ b/Modules/expat/xmlrole.c
@@ -4,7 +4,7 @@
 
 #include <stddef.h>
 
-#ifdef COMPILED_FROM_DSP
+#ifdef WIN32
 #include "winconfig.h"
 #elif defined(MACOS_CLASSIC)
 #include "macconfig.h"
@@ -16,7 +16,7 @@
 #ifdef HAVE_EXPAT_CONFIG_H
 #include <expat_config.h>
 #endif
-#endif /* ndef COMPILED_FROM_DSP */
+#endif /* ndef WIN32 */
 
 #include "expat_external.h"
 #include "internal.h"
@@ -195,9 +195,9 @@
 static int PTRCALL
 prolog2(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -216,9 +216,9 @@
 static int PTRCALL
 doctype0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -264,9 +264,9 @@
 static int PTRCALL
 doctype2(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -281,9 +281,9 @@
 static int PTRCALL
 doctype3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -298,9 +298,9 @@
 static int PTRCALL
 doctype4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -318,9 +318,9 @@
 static int PTRCALL
 doctype5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -437,9 +437,9 @@
 static int PTRCALL
 entity0(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -457,9 +457,9 @@
 static int PTRCALL
 entity1(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -502,9 +502,9 @@
 static int PTRCALL
 entity3(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -519,9 +519,9 @@
 static int PTRCALL
 entity4(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -559,9 +559,9 @@
 static int PTRCALL
 entity6(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -605,9 +605,9 @@
 static int PTRCALL
 entity8(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -622,9 +622,9 @@
 static int PTRCALL
 entity9(PROLOG_STATE *state,
         int tok,
-        const char *ptr,
-        const char *end,
-        const ENCODING *enc)
+        const char *UNUSED_P(ptr),
+        const char *UNUSED_P(end),
+        const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -639,9 +639,9 @@
 static int PTRCALL
 entity10(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -656,9 +656,9 @@
 static int PTRCALL
 notation0(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -697,9 +697,9 @@
 static int PTRCALL
 notation2(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -714,9 +714,9 @@
 static int PTRCALL
 notation3(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -732,9 +732,9 @@
 static int PTRCALL
 notation4(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -753,9 +753,9 @@
 static int PTRCALL
 attlist0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -771,9 +771,9 @@
 static int PTRCALL
 attlist1(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -833,9 +833,9 @@
 static int PTRCALL
 attlist3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -852,9 +852,9 @@
 static int PTRCALL
 attlist4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -872,9 +872,9 @@
 static int PTRCALL
 attlist5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -889,9 +889,9 @@
 static int PTRCALL
 attlist6(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -906,9 +906,9 @@
 static int PTRCALL
 attlist7(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -967,9 +967,9 @@
 static int PTRCALL
 attlist9(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -984,9 +984,9 @@
 static int PTRCALL
 element0(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1072,9 +1072,9 @@
 static int PTRCALL
 element3(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1097,9 +1097,9 @@
 static int PTRCALL
 element4(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1115,9 +1115,9 @@
 static int PTRCALL
 element5(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1136,9 +1136,9 @@
 static int PTRCALL
 element6(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1166,9 +1166,9 @@
 static int PTRCALL
 element7(PROLOG_STATE *state,
          int tok,
-         const char *ptr,
-         const char *end,
-         const ENCODING *enc)
+         const char *UNUSED_P(ptr),
+         const char *UNUSED_P(end),
+         const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1240,9 +1240,9 @@
 static int PTRCALL
 condSect1(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1258,9 +1258,9 @@
 static int PTRCALL
 condSect2(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1277,9 +1277,9 @@
 static int PTRCALL
 declClose(PROLOG_STATE *state,
           int tok,
-          const char *ptr,
-          const char *end,
-          const ENCODING *enc)
+          const char *UNUSED_P(ptr),
+          const char *UNUSED_P(end),
+          const ENCODING *UNUSED_P(enc))
 {
   switch (tok) {
   case XML_TOK_PROLOG_S:
@@ -1292,11 +1292,11 @@
 }
 
 static int PTRCALL
-error(PROLOG_STATE *state,
-      int tok,
-      const char *ptr,
-      const char *end,
-      const ENCODING *enc)
+error(PROLOG_STATE *UNUSED_P(state),
+      int UNUSED_P(tok),
+      const char *UNUSED_P(ptr),
+      const char *UNUSED_P(end),
+      const ENCODING *UNUSED_P(enc))
 {
   return XML_ROLE_NONE;
 }