Zend: silence -Warray-bounds false positive in zend_vm_init_call_frame

ZEND_CLOSURE_OBJECT() steps back from the func pointer to the enclosing
zend_closure; under -O2 GCC reads that as an out-of-bounds access of
func and -Werror=array-bounds fails the build. The access is valid
(func is embedded in the closure), so guard it with a localized GCC
diagnostic pragma. Needed for --enable-werror release builds.

Author: henderkes

Zend/zend_execute.h

@@ -345,9 +345,18 @@ static zend_always_inline void zend_vm_init_call_frame(zend_execute_data *call,
 	 * call-frame teardown skips destroying it. VERIFY_GENERIC_ARGUMENTS may
 	 * still overwrite type_args later for explicit-turbofish calls. */
 	if (UNEXPECTED(func->common.fn_flags & ZEND_ACC_CLOSURE)) {
+		/* ZEND_CLOSURE_OBJECT() steps back from func to the enclosing closure;
+		 * GCC's -Warray-bounds wrongly reads that as out-of-bounds of func. */
+#if defined(__GNUC__) && !defined(__clang__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
 		const zend_closure *closure =
 			(const zend_closure *) ZEND_CLOSURE_OBJECT(func);
 		call->type_args = closure->captured_type_args;
+#if defined(__GNUC__) && !defined(__clang__)
+# pragma GCC diagnostic pop
+#endif
 	} else if (UNEXPECTED(ZEND_USER_CODE(func->type)
 			&& (func->op_array.fn_flags2 & ZEND_ACC2_MONOMORPH_TYPE_ARGS))) {
 		/* Monomorph reached via by-name dispatch: bind its concrete type-arg table. */