Add more C headers

[steple]

I stumbled upon these.

[martis42]

@steple
Thanks for proposing this. I won't accept this PR. Not because I reject the proposal itself, but because I want to consistently add all C library and POSIX C library headers. The current list was based on https://en.cppreference.com/w/cpp/header which however ignores many common C headers.

[martis42]

P.S.: If you need a fast solution you can provide yourself include statements which shall be ignored, see this example: https://github.com/martis42/depend_on_what_you_use/tree/main/examples/ignoring_includes

[steple]

extra_ignore_include_paths works perfectly for my use case, thank you.

[martis42]

@steple
#248 should help with your issue in the long term.