fix assembly of safe_address() for x86 and x86_64

Zend/zend_alloc.c

@@ -2386,7 +2386,7 @@ static inline size_t safe_address(size_t nmemb, size_t size, size_t offset)
 	size_t res = nmemb;
 	unsigned long overflow = 0;
 
-	__asm__ ("mull %3\n\taddl %4,%0\n\tadcl %1,%1"
+	__asm__ ("mull %3\n\taddl %4,%0\n\tadcl $0,%1"
 	     : "=&a"(res), "=&d" (overflow)
 	     : "%0"(res),
 	       "rm"(size),
@@ -2406,7 +2406,7 @@ static inline size_t safe_address(size_t nmemb, size_t size, size_t offset)
         size_t res = nmemb;
         unsigned long overflow = 0;
 
-        __asm__ ("mulq %3\n\taddq %4,%0\n\tadcq %1,%1"
+        __asm__ ("mulq %3\n\taddq %4,%0\n\tadcq $0,%1"
              : "=&a"(res), "=&d" (overflow)
              : "%0"(res),
                "rm"(size),