Does not work for GUUID validation

Hello, it seems that it does not work for GUUID validation

```
const char* pattern = "^([0-9A-Fa-f]{8}[-][0-9A-Fa-f]{4}[-][0-9A-Fa-f]{4}[-][0-9A-Fa-f]{4}[-][0-9A-Fa-f]{12})$";
int m = re_match(pattern, "CA761232-ED42-11CE-BACD-00AA0057B223");
```

This works with online tools https://regex101.com/r/hD8sJ8/3

Thank you

Start at the re_match entry point in the tiny-regex-c code and reproduce the supplied UUID pattern and input. Trace why the expression does not match as expected, then verify the behavior with a regression test covering this example. Done means the reported UUID is accepted without breaking existing regex behavior.

Written by the indexing model from the issue text.