Case-insensitive regexes were useful

[Dr-Emann]

I think case insensitivity (unicode-case) was useful:

--allowlist-item '(?i)(aaa|bbb).*' used to work for e.g. AAA_CONST, and bbb_func()

Now it (silently 😲) matches nothing.

As a workaround, it looks like for my case I can use --allowlist-item '(?i-u:aaa|bbb).*', which turns on case insensitivity, and turns off unicode matching for my literal prefixes.

Originally posted by @Dr-Emann in https://github.com/rust-lang/rust-bindgen/issues/2702#issuecomment-1940389007