TEST: Drop the check for stdint.h

curl now expects C99-style fixed-length types to be defined, and the
standard location for that is stdint.h. There is no need to check for a
header file that must exist.

Caveats:
- Some systems predating C99 defined the necessary types in inttypes.h,
  but this PR doesn't affect those.
- Apparently, OS400 doesn't define uintptr_t but does have stdint.h, so
  this PR will probably break it. The uintptr_t dependencies should
  probably be guarded by a new HAVE_UINTPTR_T macro (or maybe
  MISSING_UINTPTR_T) to use alternate code there.

Ref: #20384

.github/scripts/cmp-config.pl

@@ -71,7 +71,6 @@ my %remove = (
     '#define HAVE_QUICHE_H 1' => 1,
     '#define HAVE_SSL_SET_QUIC_TLS_CBS 1' => 1,
     '#define HAVE_SSL_SET_QUIC_USE_LEGACY_CODEPOINT 1' => 1,
-    '#define HAVE_STDINT_H 1' => 1,
     '#define HAVE_STDIO_H 1' => 1,
     '#define HAVE_STDLIB_H 1' => 1,
     '#define HAVE_STRING_H 1' => 1,

CMake/unix-cache.cmake

@@ -243,7 +243,6 @@ set(HAVE_SOCKETPAIR 1)
 set(HAVE_STDATOMIC_H 1)
 set(HAVE_STDBOOL_H 1)
 set(HAVE_STDDEF_H 1)
-set(HAVE_STDINT_H 1)
 set(HAVE_STRCASECMP 1)
 set(HAVE_STRCMPI 0)
 set(HAVE_STRDUP 1)

CMake/win32-cache.cmake

@@ -36,7 +36,6 @@ if(MINGW)
   set(HAVE_SNPRINTF 1)
   set(HAVE_STDBOOL_H 1)
   set(HAVE_STDDEF_H 1)  # detected by CMake internally in check_type_size()
-  set(HAVE_STDINT_H 1)  # detected by CMake internally in check_type_size()
   set(HAVE_STRINGS_H 1)  # wrapper to string.h
   set(HAVE_SYS_PARAM_H 1)
   set(HAVE_UNISTD_H 1)
@@ -53,7 +52,6 @@ else()
   if(MSVC)
     set(HAVE_UNISTD_H 0)
     set(HAVE_STDDEF_H 1)  # detected by CMake internally in check_type_size()
-    set(HAVE_STDINT_H 1)  # detected by CMake internally in check_type_size()
     if(MSVC_VERSION GREATER_EQUAL 1800)
       set(HAVE_STDBOOL_H 1)
     else()

CMakeLists.txt

@@ -1494,7 +1494,6 @@ check_include_file("poll.h"           HAVE_POLL_H)
 check_include_file("pwd.h"            HAVE_PWD_H)
 check_include_file("stdatomic.h"      HAVE_STDATOMIC_H)
 check_include_file("stdbool.h"        HAVE_STDBOOL_H)
-check_include_file("stdint.h"         HAVE_STDINT_H)
 check_include_file("strings.h"        HAVE_STRINGS_H)
 check_include_file("stropts.h"        HAVE_STROPTS_H)
 check_include_file("termio.h"         HAVE_TERMIO_H)

lib/config-win32.h

@@ -46,11 +46,6 @@
 #define HAVE_STDBOOL_H 1
 #endif
 
-/* Define to 1 if you have the <stdint.h> header file. */
-#if defined(_MSC_VER) || defined(__MINGW32__)
-#define HAVE_STDINT_H 1
-#endif
-
 /* Define if you have the <sys/param.h> header file. */
 #ifdef __MINGW32__
 #define HAVE_SYS_PARAM_H 1

lib/curl_config-cmake.h.in

@@ -472,9 +472,6 @@
 /* Define to 1 if you have the sendmmsg function. */
 #cmakedefine HAVE_SENDMMSG 1
 
-/* Define to 1 if you have the <stdint.h> header file. */
-#cmakedefine HAVE_STDINT_H 1
-
 /* Define to 1 if you have the 'fsetxattr' function. */
 #cmakedefine HAVE_FSETXATTR 1
 

lib/curl_setup.h

@@ -466,9 +466,7 @@
 #include <curl/stdcheaders.h>
 #endif
 
-#if defined(HAVE_STDINT_H) || defined(USE_WOLFSSL)
 #include <stdint.h>
-#endif
 
 #ifdef __DJGPP__
 /* By default, DJGPP provides this type as a version of 'unsigned long' which

lib/curl_setup_once.h

@@ -62,11 +62,7 @@
 
 /* Macro to strip 'const' without triggering a compiler warning.
    Use it for APIs that do not or cannot support the const qualifier. */
-#ifdef HAVE_STDINT_H
-#  define CURL_UNCONST(p) ((void *)(uintptr_t)(const void *)(p))
-#else
-#  define CURL_UNCONST(p) ((void *)(p))  /* Fall back to simple cast */
-#endif
+#define CURL_UNCONST(p) ((void *)(uintptr_t)(const void *)(p))
 
 #ifdef USE_SCHANNEL
 /* Must set this before <schannel.h> is included directly or indirectly by

lib/formdata.c

@@ -310,11 +310,7 @@ static CURLFORMcode FormAdd(struct curl_httppost **httppost,
   struct curl_httppost *lastnode = NULL;
 
 #define form_ptr_arg(t) (forms ? (t)(void *)avalue : va_arg(params, t))
-#ifdef HAVE_STDINT_H
 #define form_int_arg(t) (forms ? (t)(uintptr_t)avalue : va_arg(params, t))
-#else
-#define form_int_arg(t) (forms ? (t)(void *)avalue : va_arg(params, t))
-#endif
 
   /*
    * We need to allocate the first struct to fill in.