Add #ifndef restrict

Author: dreamsxin

Zend/zend_portability.h

@@ -239,11 +239,13 @@ char *alloca();
 # define ZEND_FASTCALL
 #endif
 
-#if defined(__GNUC__) && ZEND_GCC_VERSION >= 3004
-#else
-# define __restrict__
+#ifndef restrict
+# if defined(__GNUC__) && ZEND_GCC_VERSION >= 3004
+# else
+#  define __restrict__
+# endif
+# define restrict __restrict__
 #endif
-#define restrict __restrict__
 
 #if (defined(__GNUC__) && __GNUC__ >= 3 && !defined(__INTEL_COMPILER) && !defined(DARWIN) && !defined(__hpux) && !defined(_AIX) && !defined(__osf__)) || __has_attribute(noreturn)
 # define HAVE_NORETURN