[clang-tools-extra] [clang-tidy] Support LineFilter in .clang-tidy configuration files (PR #202575)

[Peiqi Li via cfe-commits]

voyager-jhk wrote:

> Could you please explain how it solves [this](https://github.com/llvm/llvm-project/issues/59263#issuecomment-1334260442) concern:
> 
> > Moving the flag from the command line to the config likely wouldn't have any effect on clangd as it doesn't handle the options file the same way tidy does natively.
> 
> I didn't dig in this for myself now, but I suppose you've taken it into account when working on this issue.

This patch makes LineFilter available via .clang-tidy, but I haven't verified whether clangd applies it in its diagnostics pipeline.

I'll look into that and update the PR. Thanks!

https://github.com/llvm/llvm-project/pull/202575