cleanup: remove references to no longer used stdint.h

Since 19c50b9d (Unconditionally use inttypes.h instead of trying for
stdint.h (simplification) and remove the now unnecessary inclusion in
pcre2_internal.h., 2018-11-14), stdint.h is no longer used.

Remove checks for it in autotools and CMake and document better the
expected build failures for systems that might have stdint.h (C99)
and not inttypes.h (from POSIX), like old Windows.

CMakeLists.txt

@@ -134,7 +134,6 @@ INCLUDE(CheckTypeSize)
 INCLUDE(GNUInstallDirs) # for CMAKE_INSTALL_LIBDIR
 
 CHECK_INCLUDE_FILE(dirent.h     HAVE_DIRENT_H)
-CHECK_INCLUDE_FILE(stdint.h     HAVE_STDINT_H)
 CHECK_INCLUDE_FILE(inttypes.h   HAVE_INTTYPES_H)
 CHECK_INCLUDE_FILE(sys/stat.h   HAVE_SYS_STAT_H)
 CHECK_INCLUDE_FILE(sys/types.h  HAVE_SYS_TYPES_H)

NON-AUTOTOOLS-BUILD

@@ -343,7 +343,7 @@ cache can be deleted by selecting "File > Delete Cache".
 
 BUILDING PCRE2 ON WINDOWS WITH VISUAL STUDIO
 
-The code currently cannot be compiled without a stdint.h header, which is
+The code currently cannot be compiled without an inttypes.h header, which is
 available only in relatively recent versions of Visual Studio. However, this
 portable and permissively-licensed implementation of the header worked without
 issue:

config-cmake.h.in

@@ -3,7 +3,6 @@
 #cmakedefine HAVE_ATTRIBUTE_UNINITIALIZED 1
 #cmakedefine HAVE_DIRENT_H 1
 #cmakedefine HAVE_INTTYPES_H 1    
-#cmakedefine HAVE_STDINT_H 1                                                   
 #cmakedefine HAVE_STRERROR 1
 #cmakedefine HAVE_SYS_STAT_H 1
 #cmakedefine HAVE_SYS_TYPES_H 1

src/config.h.generic

@@ -109,9 +109,6 @@ sure both macros are undefined; an emulation function will then be used. */
 /* Define to 1 if you have the `secure_getenv' function. */
 /* #undef HAVE_SECURE_GETENV */
 
-/* Define to 1 if you have the <stdint.h> header file. */
-/* #undef HAVE_STDINT_H */
-
 /* Define to 1 if you have the <stdio.h> header file. */
 /* #undef HAVE_STDIO_H */
 

src/config.h.in

@@ -109,9 +109,6 @@ sure both macros are undefined; an emulation function will then be used. */
 /* Define to 1 if you have the `secure_getenv' function. */
 #undef HAVE_SECURE_GETENV
 
-/* Define to 1 if you have the <stdint.h> header file. */
-#undef HAVE_STDINT_H
-
 /* Define to 1 if you have the <stdio.h> header file. */
 #undef HAVE_STDIO_H
 

src/pcre2.h.generic

@@ -84,8 +84,8 @@ set, we ensure here that it has no effect. */
 /* Have to include limits.h, stdlib.h, and inttypes.h to ensure that size_t and
 uint8_t, UCHAR_MAX, etc are defined. Some systems that do have inttypes.h do
 not have stdint.h, which is why we use inttypes.h, which according to the C
-standard is a superset of stdint.h. If none of these headers are available,
-the relevant values must be provided by some other means. */
+standard is a superset of stdint.h. If inttypes.h is not available the build
+will break and the relevant values must be provided by some other means. */
 
 #include <limits.h>
 #include <stdlib.h>

src/pcre2.h.in

@@ -84,8 +84,8 @@ set, we ensure here that it has no effect. */
 /* Have to include limits.h, stdlib.h, and inttypes.h to ensure that size_t and
 uint8_t, UCHAR_MAX, etc are defined. Some systems that do have inttypes.h do
 not have stdint.h, which is why we use inttypes.h, which according to the C
-standard is a superset of stdint.h. If none of these headers are available,
-the relevant values must be provided by some other means. */
+standard is a superset of stdint.h. If inttypes.h is not available the build
+will break and the relevant values must be provided by some other means. */
 
 #include <limits.h>
 #include <stdlib.h>