Add include guard to php_config.h/config.w32.h

Header inclusion guard was added upstream in PHP 8.5. This syncs it with
upstream except in CMake also PHP 8.3 and 8.4 are guarded for multiple
inclusions.

Author: petk

cmake/main/CMakeLists.txt

@@ -311,9 +311,11 @@ endfunction()
 # Configure main configuration header (php_config.h, config.w32.h).
 function(_php_main_configure_php_config)
   if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
+    set(PHP_CONFIG_HEADER_GUARD "CONFIG_W32_H")
     set(PHP_CONFIG_H_WINDOWS 1)
     set(file config.w32.h)
   else()
+    set(PHP_CONFIG_HEADER_GUARD "PHP_CONFIG_H")
     set(PHP_CONFIG_H_WINDOWS 0)
     set(file php_config.h)
     set(HAVE_BUILD_DEFS_H TRUE)

cmake/main/cmake/php_config.h.in

@@ -1,4 +1,5 @@
-#if !defined(PHP_CONFIG_H) || @PHP_CONFIG_H_WINDOWS@
+#ifndef @PHP_CONFIG_HEADER_GUARD@
+#define @PHP_CONFIG_HEADER_GUARD@
 
 #if @PHP_CONFIG_H_WINDOWS@
 /* Define the minimum supported version */
@@ -28,8 +29,6 @@
 # define STDOUT_FILENO 1
 # define STDERR_FILENO 2
 #else
-# define PHP_CONFIG_H
-
 # if defined(__GNUC__) && __GNUC__ >= 4
 #  define ZEND_API __attribute__ ((visibility("default")))
 #  define ZEND_DLEXPORT __attribute__ ((visibility("default")))
@@ -730,4 +729,4 @@
 # include <string.h>
 #endif
 
-#endif /* PHP_CONFIG_H */
+#endif /* @PHP_CONFIG_HEADER_GUARD@ */