use zend_simd.h in mbstring

Author: SakiTakamachi

ext/mbstring/mbstring.c

@@ -65,9 +65,7 @@
 
 #include "rare_cp_bitvec.h"
 
-#ifdef __SSE2__
-#include <emmintrin.h>
-#endif
+#include "zend_simd.h"
 
 #ifdef __SSE3__
 #include <immintrin.h>
@@ -1749,7 +1747,7 @@ PHP_FUNCTION(mb_str_split)
 	}
 }
 
-#ifdef __SSE2__
+#ifdef XSSE2
 /* Thanks to StackOverflow user 'Paul R' (https://stackoverflow.com/users/253056/paul-r)
  * From: https://stackoverflow.com/questions/36998538/fastest-way-to-horizontally-sum-sse-unsigned-byte-vector
  * Takes a 128-bit XMM register, treats each byte as an 8-bit integer, and sums up all
@@ -1780,7 +1778,7 @@ static size_t mb_fast_strlen_utf8(unsigned char *p, size_t len)
 {
 	unsigned char *e = p + len;
 
-#ifdef __SSE2__
+#ifdef XSSE2
 	if (len >= sizeof(__m128i)) {
 		e -= sizeof(__m128i);
 
@@ -4919,7 +4917,7 @@ MBSTRING_API bool php_mb_check_encoding(const char *input, size_t length, const
 static bool mb_fast_check_utf8_default(zend_string *str)
 {
 	unsigned char *p = (unsigned char*)ZSTR_VAL(str);
-# ifdef __SSE2__
+# ifdef XSSE2
 	/* `e` points 1 byte past the last full 16-byte block of string content
 	 * Note that we include the terminating null byte which is included in each zend_string
 	 * as part of the content to check; this ensures that multi-byte characters which are