Check for undef variable exception in SEND_VAR JIT

Add a return value to zend_jit_undefined_op_helper(), so we can
check for exception based on the return value, instead of fetching
EG(exception).

Author: nikic

ext/opcache/jit/zend_jit_helpers.c

@@ -278,12 +278,13 @@ static zval* ZEND_FASTCALL zend_jit_symtable_lookup_w(HashTable *ht, zend_string
 	return retval;
 }
 
-static void ZEND_FASTCALL zend_jit_undefined_op_helper(uint32_t var)
+static int ZEND_FASTCALL zend_jit_undefined_op_helper(uint32_t var)
 {
 	const zend_execute_data *execute_data = EG(current_execute_data);
 	zend_string *cv = EX(func)->op_array.vars[EX_VAR_TO_NUM(var)];
 
 	zend_error(E_WARNING, "Undefined variable $%s", ZSTR_VAL(cv));
+	return EG(exception) == NULL;
 }
 
 static void ZEND_FASTCALL zend_jit_fetch_dim_r_helper(zend_array *ht, zval *dim, zval *result)

ext/opcache/jit/zend_jit_x86.dasc

@@ -9235,6 +9235,8 @@ static int zend_jit_send_var(dasm_State **Dst, const zend_op *opline, const zend
 		|	mov FCARG1d, opline->op1.var
 		|	EXT_CALL zend_jit_undefined_op_helper, r0
 		|	SET_ZVAL_TYPE_INFO arg_addr, IS_NULL
+		|	test r0, r0
+		|	jz ->exception_handler
 
 		if (op1_info & (MAY_BE_ANY|MAY_BE_REF)) {
 			|	jmp >7