### Godot version

4.0.3

### System information

Win7

### Issue description

![image](https://github.com/godotengine/godot/assets/28286958/abec9d3c-e078-424c-9430-d9fe8897aad6)


### Steps to reproduce

1. Create shader
2. Add uint with hex, e.g. 0xffffu

### Minimal reproduction project

N/A
identifier = StringName();
	TkPos pos = { 0, 0 };
	Token tk = _get_token();
	if (tk.type == TK_IDENTIFIER) {
		identifier = tk.text;
		pos = _get_tkpos();
		tk = _get_token();
	}
	if (tk.type == TK_CURSOR) {
		completion_type = p_type;
		completion_line = tk_line;
		completion_block = p_block;
		pos = _get_tkpos();
		tk = _get_token();
		if (tk.type == TK_IDENTIFIER) {
			identifier = identifier.operator String() + tk.text.operator String();
		} else {
			_set_tkpos(pos);
		}
		return true;
	} else if (identifier != StringName()) {
		_set_tkpos(pos);
	}
	return false;
}
bool ShaderLanguage::_is_operator_assign(Operator p_op) const {