+Backport of:
+
+https://github.com/php/php-src/commit/8c8679207ae5ada8751288e75b78c928a4d34d1d
+
+diff -u -r ../php-7.1.7/Zend/zend_multiply.h ./Zend/zend_multiply.h
+--- ../php-7.1.7/Zend/zend_multiply.h 2017-07-06 11:30:11.000000000 +0200
++++ ./Zend/zend_multiply.h 2017-07-10 00:54:43.550300703 +0200
+@@ -53,8 +53,8 @@
+ __asm__("mul %0, %2, %3\n" \
+ "smulh %1, %2, %3\n" \
+ "sub %1, %1, %0, asr #63\n" \
+- : "=X"(__tmpvar), "=X"(usedval) \
+- : "X"(a), "X"(b)); \
++ : "=&r"(__tmpvar), "=&r"(usedval) \
++ : "r"(a), "r"(b)); \
+ if (usedval) (dval) = (double) (a) * (double) (b); \
+ else (lval) = __tmpvar; \
+ } while (0)