ext/gmp: fix bug16502 test expected error message

Author: arshidkv12

ext/gmp/gmp.c

@@ -372,10 +372,11 @@ static zend_result shift_operator_helper(gmp_binary_ui_op_t op, zval *return_val
 			goto typeof_op_failure;
 		}
 
-		if (shift > SHRT_MAX && opcode == ZEND_POW) {
+		if (shift > INT_MAX / 1000) {
 			zend_throw_error(
-				zend_ce_value_error, "Exponent must be less than %d",
-				SHRT_MAX
+				zend_ce_value_error, "%s must be less than %d",
+				opcode == ZEND_POW ? "Exponent" : "Shift",
+				(INT_MAX / 1000)
 			);
 			ZVAL_UNDEF(return_value);
 			return FAILURE;