Remove HAVE_STDARG_H

The C89 standard and later defines the `<stdarg.h>` header as part of
the standard headers [1]. On current systems it is always present and
can be included unconditionally.

Checking for presence and functionality of the `<stdarg.h>` header and
variadic function is not relevant anymore on current systems since this
is always available.

Also Autoconf suggests relying on at least C89 or above [2] and [3].

The following files were regenerated with re2c 1.0.3:
- Zend/zend_language_scanner.c
- Zend/zend_language_scanner_defs.h

Refs:
[1] https://port70.net/~nsz/c/c89/c89-draft.html#4.1.2
[2] http://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/headers.m4
[3] https://www.gnu.org/software/autoconf/manual/autoconf-2.69/autoconf.html

TSRM/TSRM.c

@@ -15,10 +15,7 @@
 #ifdef ZTS
 
 #include <stdio.h>
-
-#if HAVE_STDARG_H
 #include <stdarg.h>
-#endif
 
 typedef struct _tsrm_tls_entry tsrm_tls_entry;
 

TSRM/tsrm.m4

@@ -7,8 +7,6 @@ dnl AC_REQUIRE([AM_PROG_CC_STDC])dnl
 AC_REQUIRE([AC_PROG_CC_C_O])dnl
 AC_REQUIRE([AC_PROG_RANLIB])dnl
 
-AC_CHECK_HEADERS(stdarg.h)
-
 AC_CHECK_FUNCS(sigprocmask)
 
 AX_FUNC_WHICH_GETHOSTBYNAME_R()

Zend/Zend.m4

@@ -51,7 +51,6 @@ stdint.h \
 limits.h \
 malloc.h \
 unistd.h \
-stdarg.h \
 sys/types.h \
 sys/time.h \
 signal.h \

Zend/zend_API.c

@@ -30,9 +30,7 @@
 #include "zend_closures.h"
 #include "zend_inheritance.h"
 
-#ifdef HAVE_STDARG_H
 #include <stdarg.h>
-#endif
 
 /* these variables are true statics/globals, and have to be mutex'ed on every access */
 ZEND_API HashTable module_registry;

Zend/zend_compile.h

@@ -23,9 +23,7 @@
 #include "zend.h"
 #include "zend_ast.h"
 
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 #include "zend_llist.h"
 

Zend/zend_language_scanner.l

@@ -75,9 +75,7 @@
 # error ZEND_MMAP_AHEAD should be greater than or equal to YYMAXFILL
 #endif
 
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>

Zend/zend_language_scanner_defs.h

@@ -1,4 +1,4 @@
-/* Generated by re2c 1.0.1 */
+/* Generated by re2c 1.0.3 */
 #line 3 "Zend/zend_language_scanner_defs.h"
 
 enum YYCONDTYPE {

Zend/zend_portability.h

@@ -54,9 +54,7 @@
 # include <unix.h>
 #endif
 
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 #ifdef HAVE_DLFCN_H
 # include <dlfcn.h>

Zend/zend_ptr_stack.c

@@ -19,9 +19,7 @@
 
 #include "zend.h"
 #include "zend_ptr_stack.h"
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 ZEND_API void zend_ptr_stack_init_ex(zend_ptr_stack *stack, zend_bool persistent)
 {

Zend/zend_sprintf.c

@@ -21,9 +21,7 @@
 
 #include "zend.h"
 
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 #if ZEND_BROKEN_SPRINTF
 int zend_sprintf(char *buffer, const char *format, ...)

Zend/zend_virtual_cwd.h

@@ -32,9 +32,7 @@
 #include <utime.h>
 #endif
 
-#ifdef HAVE_STDARG_H
 #include <stdarg.h>
-#endif
 
 #ifdef ZTS
 #define VIRTUAL_DIR

configure.ac

@@ -442,7 +442,6 @@ poll.h \
 pwd.h \
 resolv.h \
 signal.h \
-stdarg.h \
 syslog.h \
 sysexits.h \
 sys/ioctl.h \

ext/mbstring/config.m4

@@ -77,24 +77,7 @@ AC_DEFUN([PHP_MBSTRING_SETUP_MBREGEX], [
         AC_DEFINE([USE_COMBINATION_EXPLOSION_CHECK],1,[whether to check multibyte regex backtrack])
       fi
 
-      AC_CACHE_CHECK(for variable length prototypes and stdarg.h, php_cv_mbstring_stdarg, [
-        AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#include <stdarg.h>
-int foo(int x, ...) {
-  va_list va;
-  va_start(va, x);
-  va_arg(va, int);
-  va_arg(va, char *);
-  va_arg(va, double);
-  return 0;
-}
-int main() { return foo(10, "", 3.14); }
-        ]])], [php_cv_mbstring_stdarg=yes], [php_cv_mbstring_stdarg=no], [
-          php_cv_mbstring_stdarg=no
-        ])
-      ])
-
-      AC_CHECK_HEADERS([strings.h unistd.h sys/time.h sys/times.h stdarg.h limits.h])
+      AC_CHECK_HEADERS([strings.h unistd.h sys/time.h sys/times.h limits.h])
       AC_CHECK_SIZEOF(int, 4)
       AC_CHECK_SIZEOF(short, 2)
       AC_CHECK_SIZEOF(long, 4)

win32/build/config.w32.h.in

@@ -104,7 +104,6 @@
 #define HAVE_SYSLOG_H 1
 #undef HAVE_UNISTD_H
 #define HAVE_SYS_TYPES_H 1
-#define HAVE_STDARG_H 1
 #undef HAVE_ALLOCA_H
 #undef HAVE_KILL
 #define HAVE_GETPID 1