Less conservative fix

I think it's reasonable to assume that the only possible types
are those that are declared, and null, because null is what
return_value is initialized to.

Author: nikic

ext/opcache/jit/zend_jit_x86.dasc

@@ -8463,17 +8463,15 @@ static int zend_jit_do_fcall(dasm_State **Dst, const zend_op *opline, const zend
 		|1:
 
 		if (!RETURN_VALUE_USED(opline)) {
-#if 0
-			/* If an exception is thrown, then the value stored in the return_value slot
-			 * may have a different type. */
 			zend_class_entry *ce;
 			zend_bool ce_is_instanceof;
 			uint32_t func_info = call_info ?
 				zend_get_func_info(call_info, ssa, &ce, &ce_is_instanceof) :
 				(MAY_BE_ANY|MAY_BE_REF|MAY_BE_RC1|MAY_BE_RCN);
-#else
-			uint32_t func_info = (MAY_BE_ANY|MAY_BE_REF|MAY_BE_RC1|MAY_BE_RCN);
-#endif
+
+			/* If an exception is thrown, the return_value may stay at the
+			 * original value of null. */
+			func_info |= MAY_BE_NULL;
 
 			if (func_info & (MAY_BE_STRING|MAY_BE_ARRAY|MAY_BE_OBJECT|MAY_BE_RESOURCE|MAY_BE_REF)) {
 				|	ZVAL_PTR_DTOR res_addr, func_info, 1, 1, opline