Remove obsolescent AC_HEADER_STDC and memcpy check

Autoconf 2.59d (released in 2006) [1] started promoting several macros
as not relevant for newer systems anymore, including the `AC_HEADER_STDC`.

This macro checks if given system has C89 compliant header files such
as `<string.h>`, `<stdlib.h>`, `<stdarg.h>`, `<float.h>`,... and defines
the `STDC_HEADERS` symbol [2]. Case is that current systems should be
well supported with at least C89 standard headers [3].

Given headers are still additionally checked with the `AC_PROG_CC`
macro, yet not needed anyway.

Additionally, the HAVE_MEMCPY check has been removed. The memcpy
function is standardized by C89 and later.

Refs:
[1] http://git.savannah.gnu.org/cgit/autoconf.git/tree/NEWS
[2] https://www.gnu.org/software/autoconf/manual/autoconf-2.69/autoconf.html
[3] https://port70.net/~nsz/c/c89/c89-draft.html#4.1.2

Author: petk

Zend/Zend.m4

@@ -29,7 +29,6 @@ AC_DEFUN([LIBZEND_BASIC_CHECKS],[
 AC_REQUIRE([AC_PROG_YACC])
 AC_REQUIRE([AC_PROG_CC])
 AC_REQUIRE([AC_PROG_CC_C_O])
-AC_REQUIRE([AC_HEADER_STDC])
 
 LIBZEND_BISON_CHECK
 
@@ -79,7 +78,7 @@ LIBZEND_CHECK_INT_TYPE(uint32_t)
 
 dnl Checks for library functions.
 AC_FUNC_ALLOCA
-AC_CHECK_FUNCS(memcpy strdup getpid kill strtod strtol finite fpclass sigsetjmp)
+AC_CHECK_FUNCS(strdup getpid kill strtod strtol finite fpclass sigsetjmp)
 
 AC_CHECK_DECLS([isfinite, isnan, isinf], [], [], [[#include <math.h>]])
 

acinclude.m4

@@ -1030,10 +1030,8 @@ AC_DEFUN([_PHP_CHECK_SIZEOF], [
     old_LDFLAGS=$LDFLAGS
     LDFLAGS=
     AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h>
-#if STDC_HEADERS
 #include <stdlib.h>
 #include <stddef.h>
-#endif
 #ifdef HAVE_INTTYPES_H
 #include <inttypes.h>
 #endif
@@ -1103,10 +1101,8 @@ AC_CACHE_VAL(ac_cv_type_in_addr_t,
 changequote(<<,>>)dnl
 <<in_addr_t[^a-zA-Z_0-9]>>dnl
 changequote([,]), [#include <sys/types.h>
-#if STDC_HEADERS
 #include <stdlib.h>
 #include <stddef.h>
-#endif
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif], ac_cv_type_in_addr_t=yes, ac_cv_type_in_addr_t=no)])dnl

configure.ac

@@ -417,9 +417,6 @@ PHP_CHECK_FUNC(inet_aton, resolv, bind)
 dnl Then headers.
 dnl -------------------------------------------------------------------------
 
-dnl Checks for header files.
-AC_HEADER_STDC
-
 dnl QNX requires unix.h to allow functions in libunix to work properly
 AC_CHECK_HEADERS([ \
 inttypes.h \
@@ -629,7 +626,6 @@ localtime_r \
 lockf \
 lchown \
 lrand48 \
-memcpy \
 memmove \
 mkstemp \
 mmap \

ext/json/config.m4

@@ -5,7 +5,6 @@ PHP_ARG_ENABLE(json, whether to enable JavaScript Object Serialization support,
 
 if test "$PHP_JSON" != "no"; then
   AC_DEFINE([HAVE_JSON],1 ,[whether to enable JavaScript Object Serialization support])
-  AC_HEADER_STDC
 
 PHP_NEW_EXTENSION(json,
 	  json.c \

ext/mbstring/libmbfl/config.h.in

@@ -63,9 +63,6 @@
 /* Define to the version of this package. */
 #undef PACKAGE_VERSION
 
-/* Define to 1 if you have the ANSI C header files. */
-#undef STDC_HEADERS
-
 /* Version number of package */
 #undef VERSION
 

ext/xmlrpc/libxmlrpc/acinclude.m4

@@ -6,12 +6,11 @@ AC_DEFUN([XMLRPC_FUNCTION_CHECKS],[
 AC_CHECK_FUNCS( \
  strtoul strtoull snprintf \
  strstr strpbrk strerror\
- memcpy memmove)
+ memmove)
 
 ])
 
 AC_DEFUN([XMLRPC_HEADER_CHECKS],[
-AC_HEADER_STDC
 AC_CHECK_HEADERS(xmlparse.h xmltok.h strings.h)
 ])
 

main/php.h

@@ -230,17 +230,7 @@ typedef unsigned int socklen_t;
 #include "zend_hash.h"
 #include "zend_alloc.h"
 #include "zend_stack.h"
-
-#if STDC_HEADERS
-# include <string.h>
-#else
-# ifndef HAVE_MEMCPY
-#  define memcpy(d, s, n)	bcopy((s), (d), (n))
-# endif
-# ifndef HAVE_MEMMOVE
-#  define memmove(d, s, n)	bcopy ((s), (d), (n))
-# endif
-#endif
+#include <string.h>
 
 #ifndef HAVE_STRERROR
 char *strerror(int);

win32/build/config.w32.h.in

@@ -69,13 +69,11 @@
 #undef HAVE_STRUCT_STAT_ST_BLKSIZE
 #undef HAVE_STRUCT_STAT_ST_BLOCKS
 #define HAVE_STRUCT_STAT_ST_RDEV 1
-#define STDC_HEADERS 1
 #define REGEX 1
 #define HSREGEX 1
 #define HAVE_GCVT 1
 #define HAVE_GETLOGIN 1
 #define HAVE_GETTIMEOFDAY 1
-#define HAVE_MEMCPY 1
 #define HAVE_MEMMOVE 1
 #define HAVE_PUTENV 1
 #define HAVE_REGCOMP 1