Upgrade to expat 2.2.6.

From `Changes`:

  Release 2.2.6 Sun August 12 2018
        Bug fixes:
       #170 #206  Avoid doing arithmetic with NULL pointers in XML_GetBuffer
       #204 #205  Fix 2.2.5 regression with suspend-resume while parsing
                    a document like '<root/>'

        Other changes:
       #165 #168  Autotools: Fix docbook-related configure syntax error
            #166  Autotools: Avoid grep option `-q` for Solaris
            #167  Autotools: Support
                    ./configure DOCBOOK_TO_MAN="xmlto man --skip-validation"
       #159 #167  Autotools: Support DOCBOOK_TO_MAN command which produces
                    xmlwf.1 rather than XMLWF.1; also covers case insensitive
                    file systems
            #181  Autotools: Drop -rpath option passed to libtool
            #188  Autotools: Detect and deny SGML docbook2man as ours is XML
            #188  Autotools/CMake: Support command db2x_docbook2man as well
            #174  CMake: Introduce option WARNINGS_AS_ERRORS, defaults to OFF
       #184 #185  CMake: Introduce option MSVC_USE_STATIC_CRT, defaults to OFF
       #207 #208  CMake: Introduce option XML_UNICODE and XML_UNICODE_WCHAR_T,
                    both defaulting to OFF
            #175  CMake: Prefer check_symbol_exists over check_function_exists
            #176  CMake: Create the same pkg-config file as with GNU Autotools
       #178 #179  CMake: Use GNUInstallDirs module to set proper defaults for
                    install directories
            #208  CMake: Utilize expat_config.h.cmake for XML_DEV_URANDOM
            #180  Windows: Fix compilation of test suite for Visual Studio 2008
  #131 #173 #202  Address compiler warnings
  #187 #190 #200  Fix miscellaneous typos
                  Version info bumped from 7:7:6 to 7:8:6

        Special thanks to:
            Anton Maklakov
            Benjamin Peterson
            Brad King
            Franek Korta
            Frank Rast
            Joe Orton
            luzpaz
            Pedro Vicente
            Rainer Jung
            Rhodri James
            Rolf Ade
            Rolf Eike Beer
            Thomas Beutlich
            Tomasz Kłoczko

Bug: N/A
Test: cts-tradefed run cts -m CtsLibcoreTestCases -t libcore.xml.ExpatSaxParserTest
Change-Id: I39ea70944ada1553cbc721ff9fd710c1937c7244
diff --git a/configure b/configure
index f24a68a..b5ddbb6 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for expat 2.2.5.
+# Generated by GNU Autoconf 2.69 for expat 2.2.6.
 #
 # Report bugs to <expat-bugs@libexpat.org>.
 #
@@ -590,8 +590,8 @@
 # Identity of this package.
 PACKAGE_NAME='expat'
 PACKAGE_TARNAME='expat'
-PACKAGE_VERSION='2.2.5'
-PACKAGE_STRING='expat 2.2.5'
+PACKAGE_VERSION='2.2.6'
+PACKAGE_STRING='expat 2.2.6'
 PACKAGE_BUGREPORT='expat-bugs@libexpat.org'
 PACKAGE_URL=''
 
@@ -1344,7 +1344,7 @@
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures expat 2.2.5 to adapt to many kinds of systems.
+\`configure' configures expat 2.2.6 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1414,7 +1414,7 @@
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of expat 2.2.5:";;
+     short | recursive ) echo "Configuration of expat 2.2.6:";;
    esac
   cat <<\_ACEOF
 
@@ -1540,7 +1540,7 @@
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-expat configure 2.2.5
+expat configure 2.2.6
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2084,7 +2084,7 @@
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by expat $as_me 2.2.5, which was
+It was created by expat $as_me 2.2.6, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -2953,7 +2953,7 @@
 
 # Define the identity of the package.
  PACKAGE='expat'
- VERSION='2.2.5'
+ VERSION='2.2.6'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -3051,7 +3051,7 @@
 
 
 LIBCURRENT=7   # sync
-LIBREVISION=7  # with
+LIBREVISION=8  # with
 LIBAGE=6       # CMakeLists.txt!
 
 CPPFLAGS="${CPPFLAGS} -DHAVE_EXPAT_CONFIG_H"
@@ -16651,7 +16651,7 @@
 _ACEOF
 
 if test $ac_cv_c_bigendian = unknown; then
-  as_fn_error please pre-set ac_cv_c_bigendian "unknown endianess - sorry" "$LINENO" 5
+  as_fn_error please pre-set ac_cv_c_bigendian "unknown endianness - sorry" "$LINENO" 5
 fi
 
 
@@ -16778,7 +16778,7 @@
 fi
 
 
- if echo -- "${host}" | fgrep -q mingw; then
+ if echo -- "${host}" | ${FGREP} mingw >/dev/null; then
   MINGW_TRUE=
   MINGW_FALSE='#'
 else
@@ -16786,7 +16786,7 @@
   MINGW_FALSE=
 fi
 
- if echo -- "${CPPFLAGS}${CFLAGS}" | fgrep -q XML_UNICODE; then
+ if echo -- "${CPPFLAGS}${CFLAGS}" | ${FGREP} XML_UNICODE >/dev/null; then
   UNICODE_TRUE=
   UNICODE_FALSE='#'
 else
@@ -17264,7 +17264,7 @@
 
 
 if test "x$with_docbook" != xno; then :
-  for ac_prog in docbook2x-man docbook2man docbook-to-man
+  for ac_prog in docbook2x-man db2x_docbook2man docbook2man docbook-to-man
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -17305,12 +17305,23 @@
 
   test -n "$DOCBOOK_TO_MAN" && break
 done
-test -n "$DOCBOOK_TO_MAN" || DOCBOOK_TO_MAN="if test "x$with_docbook" != xcheck; then
-    as_fn_error $? "Required program 'docbook2x-man' not found." "$LINENO" 5"
 
 fi
+if test "x${DOCBOOK_TO_MAN}" = x -a "x$with_docbook" = xyes; then :
+  as_fn_error $? "Required program 'docbook2x-man' not found." "$LINENO" 5
+fi
+if test "x${DOCBOOK_TO_MAN}" != x -a "x$with_docbook" != xno; then :
+  if ${DOCBOOK_TO_MAN} --help | grep -i -q -F sgmlbase; then :
+  as_fn_error $? "Your local ${DOCBOOK_TO_MAN} was found to work with SGML rather
+  than XML. Please install docbook2X and use variable DOCBOOK_TO_MAN to point
+  configure to command docbook2x-man of docbook2X.
+  Or use DOCBOOK_TO_MAN=\"xmlto man --skip-validation\" if you have xmlto around.
+  You can also configure using --without-docbook if you can do without a man
+  page for xmlwf." "$LINENO" 5
+fi
+fi
 
- if test x${DOCBOOK_TO_MAN} != x; then
+ if test "x${DOCBOOK_TO_MAN}" != x; then
   WITH_DOCBOOK_TRUE=
   WITH_DOCBOOK_FALSE='#'
 else
@@ -17875,7 +17886,7 @@
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by expat $as_me 2.2.5, which was
+This file was extended by expat $as_me 2.2.6, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -17941,7 +17952,7 @@
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-expat config.status 2.2.5
+expat config.status 2.2.6
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"