Remove use of register keyword in headers

Headers must be C++ compatible -- this throws warnings.

The register keyword is not used for optimization, at least not
in optimized builds.

Zend/zend_hash.h

@@ -248,7 +248,7 @@ END_EXTERN_C()
 
 static zend_always_inline int _zend_handle_numeric_str(const char *key, size_t length, zend_ulong *idx)
 {
-	register const char *tmp = key;
+	const char *tmp = key;
 
 	if (*tmp > '9') {
 		return 0;

Zend/zend_operators.h

@@ -185,7 +185,7 @@ zend_memnstr(const char *haystack, const char *needle, size_t needle_len, const
 
 static zend_always_inline const void *zend_memrchr(const void *s, int c, size_t n)
 {
-	register const unsigned char *e;
+	const unsigned char *e;
 	if (n <= 0) {
 		return NULL;
 	}

Zend/zend_string.h

@@ -323,7 +323,7 @@ static zend_always_inline zend_bool zend_string_equals(zend_string *s1, zend_str
 
 static zend_always_inline zend_ulong zend_inline_hash_func(const char *str, size_t len)
 {
-	register zend_ulong hash = Z_UL(5381);
+	zend_ulong hash = Z_UL(5381);
 
 	/* variant with the hash unrolled eight times */
 	for (; len >= 8; len -= 8) {

ext/standard/php_smart_string.h

@@ -93,7 +93,7 @@
 	smart_string_append_unsigned_ex((dest), (val), 0)
 
 #define smart_string_appendc_ex(dest, ch, what) do {					\
-	register size_t __nl;											\
+	size_t __nl;													\
 	smart_string_alloc4((dest), 1, (what), __nl);						\
 	(dest)->len = __nl;												\
 	((unsigned char *) (dest)->c)[(dest)->len - 1] = (ch);			\
@@ -109,7 +109,7 @@
 } while (0)
 
 #define smart_string_appendl_ex(dest, src, nlen, what) do {			\
-	register size_t __nl;											\
+	size_t __nl;													\
 	smart_string *__dest = (smart_string *) (dest);						\
 																	\
 	smart_string_alloc4(__dest, (nlen), (what), __nl);					\

main/php.h

@@ -330,7 +330,7 @@ END_EXTERN_C()
 BEGIN_EXTERN_C()
 PHPAPI extern int (*php_register_internal_extensions_func)(void);
 PHPAPI int php_register_internal_extensions(void);
-PHPAPI int php_mergesort(void *base, size_t nmemb, register size_t size, int (*cmp)(const void *, const void *));
+PHPAPI int php_mergesort(void *base, size_t nmemb, size_t size, int (*cmp)(const void *, const void *));
 PHPAPI void php_register_pre_request_shutdown(void (*func)(void *), void *userdata);
 PHPAPI void php_com_initialize(void);
 PHPAPI char *php_get_current_user(void);

main/snprintf.h

@@ -86,7 +86,7 @@ PHPAPI int ap_php_vasprintf(char **buf, const char *format, va_list ap);
 PHPAPI int ap_php_asprintf(char **buf, const char *format, ...);
 PHPAPI int php_sprintf (char* s, const char* format, ...) PHP_ATTRIBUTE_FORMAT(printf, 2, 3);
 PHPAPI char * php_gcvt(double value, int ndigit, char dec_point, char exponent, char *buf);
-PHPAPI char * php_conv_fp(register char format, register double num,
+PHPAPI char * php_conv_fp(char format, double num,
 		 boolean_e add_dp, int precision, char dec_point, bool_int * is_negative, char *buf, size_t *len);
 
 END_EXTERN_C()
@@ -153,11 +153,11 @@ typedef enum {
 typedef WIDE_INT wide_int;
 typedef unsigned WIDE_INT u_wide_int;
 
-PHPAPI char * ap_php_conv_10(register wide_int num, register bool_int is_unsigned,
-	   register bool_int * is_negative, char *buf_end, register size_t *len);
+PHPAPI char * ap_php_conv_10(wide_int num, bool_int is_unsigned,
+	   bool_int * is_negative, char *buf_end, size_t *len);
 
-PHPAPI char * ap_php_conv_p2(register u_wide_int num, register int nbits,
-		 char format, char *buf_end, register size_t *len);
+PHPAPI char * ap_php_conv_p2(u_wide_int num, int nbits,
+		 char format, char *buf_end, size_t *len);
 
 /* The maximum precision that's allowed for float conversion. Does not include
  * decimal separator, exponent, sign, terminator. Currently does not affect