### Godot version

4.0 beta17

### System information

Windows10

### Issue description

call `"".split()`
Is there an infinite loop inside? Function does not return.

### Steps to reproduce

"".split()

### Minimal reproduction project

N/A
String ret;
	for (int i = 0; i < parts.size(); ++i) {
		if (i > 0) {
			ret += *this;
		}
		ret += parts[i];
	}
	return ret;
}
char32_t String::char_uppercase(char32_t p_char) {