bpo-35081: Add pycore_ prefix to internal header files (GH-10263)

* Rename Include/internal/ header files:

  * pyatomic.h -> pycore_atomic.h
  * ceval.h -> pycore_ceval.h
  * condvar.h -> pycore_condvar.h
  * context.h -> pycore_context.h
  * pygetopt.h -> pycore_getopt.h
  * gil.h -> pycore_gil.h
  * hamt.h -> pycore_hamt.h
  * hash.h -> pycore_hash.h
  * mem.h -> pycore_mem.h
  * pystate.h -> pycore_state.h
  * warnings.h -> pycore_warnings.h

* PCbuild project, Makefile.pre.in, Modules/Setup: add the
  Include/internal/ directory to the search paths of header files.
* Update includes. For example, replace #include "internal/mem.h"
  with #include "pycore_mem.h".
diff --git a/Include/internal/pyatomic.h b/Include/internal/pycore_atomic.h
similarity index 100%
rename from Include/internal/pyatomic.h
rename to Include/internal/pycore_atomic.h
diff --git a/Include/internal/ceval.h b/Include/internal/pycore_ceval.h
similarity index 95%
rename from Include/internal/ceval.h
rename to Include/internal/pycore_ceval.h
index 4297b5a..ddeeb5c 100644
--- a/Include/internal/ceval.h
+++ b/Include/internal/pycore_ceval.h
@@ -4,7 +4,7 @@
 extern "C" {
 #endif
 
-#include "internal/pyatomic.h"
+#include "pycore_atomic.h"
 #include "pythread.h"
 
 struct _pending_calls {
@@ -25,7 +25,7 @@
     int last;
 };
 
-#include "internal/gil.h"
+#include "pycore_gil.h"
 
 struct _ceval_runtime_state {
     int recursion_limit;
diff --git a/Include/internal/condvar.h b/Include/internal/pycore_condvar.h
similarity index 100%
rename from Include/internal/condvar.h
rename to Include/internal/pycore_condvar.h
diff --git a/Include/internal/context.h b/Include/internal/pycore_context.h
similarity index 95%
rename from Include/internal/context.h
rename to Include/internal/pycore_context.h
index 59f88f2..57a410c 100644
--- a/Include/internal/context.h
+++ b/Include/internal/pycore_context.h
@@ -2,7 +2,7 @@
 #define Py_INTERNAL_CONTEXT_H
 
 
-#include "internal/hamt.h"
+#include "pycore_hamt.h"
 
 
 struct _pycontextobject {
diff --git a/Include/internal/pygetopt.h b/Include/internal/pycore_getopt.h
similarity index 100%
rename from Include/internal/pygetopt.h
rename to Include/internal/pycore_getopt.h
diff --git a/Include/internal/gil.h b/Include/internal/pycore_gil.h
similarity index 95%
rename from Include/internal/gil.h
rename to Include/internal/pycore_gil.h
index 7743b3f..5059850 100644
--- a/Include/internal/gil.h
+++ b/Include/internal/pycore_gil.h
@@ -4,8 +4,8 @@
 extern "C" {
 #endif
 
-#include "internal/condvar.h"
-#include "internal/pyatomic.h"
+#include "pycore_condvar.h"
+#include "pycore_atomic.h"
 
 #ifndef Py_HAVE_CONDVAR
 #  error You need either a POSIX-compatible or a Windows system!
diff --git a/Include/internal/hamt.h b/Include/internal/pycore_hamt.h
similarity index 100%
rename from Include/internal/hamt.h
rename to Include/internal/pycore_hamt.h
diff --git a/Include/internal/hash.h b/Include/internal/pycore_hash.h
similarity index 100%
rename from Include/internal/hash.h
rename to Include/internal/pycore_hash.h
diff --git a/Include/internal/mem.h b/Include/internal/pycore_mem.h
similarity index 100%
rename from Include/internal/mem.h
rename to Include/internal/pycore_mem.h
diff --git a/Include/internal/pystate.h b/Include/internal/pycore_state.h
similarity index 98%
rename from Include/internal/pystate.h
rename to Include/internal/pycore_state.h
index 38845d3..ff25d2e 100644
--- a/Include/internal/pystate.h
+++ b/Include/internal/pycore_state.h
@@ -7,9 +7,9 @@
 #include "pystate.h"
 #include "pythread.h"
 
-#include "internal/mem.h"
-#include "internal/ceval.h"
-#include "internal/warnings.h"
+#include "pycore_mem.h"
+#include "pycore_ceval.h"
+#include "pycore_warnings.h"
 
 
 /* GIL state */
diff --git a/Include/internal/warnings.h b/Include/internal/pycore_warnings.h
similarity index 100%
rename from Include/internal/warnings.h
rename to Include/internal/pycore_warnings.h
diff --git a/Include/pystate.h b/Include/pystate.h
index 8860f12..7fc921e 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -250,7 +250,7 @@
 #endif
 #ifdef Py_BUILD_CORE
    /* Macro which should only be used for performance critical code.
-      Need "#include "internal/pystate.h". See also _PyInterpreterState_Get()
+      Need "#include "pycore_state.h". See also _PyInterpreterState_Get()
       and _PyGILState_GetInterpreterStateUnsafe(). */
 #  define _PyInterpreterState_GET_UNSAFE() (PyThreadState_GET()->interp)
 #endif