[clang] [alpha.webkit.UncheckedLambdaCapturesChecker] Split unchecked lambda capture checker (PR #201044)

[Balázs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

Inheriting from an existing checker is orthodox. This would be a problem if the checker would do path-sensitive analysis, because the path-sensitive bug reports inherit their tags from the checker - thus both of the base and the derived checkers would have the same tags, and attribute the bug to the same (base) checker.

I think, ideally we had 2 commits (or PRs). One that does the NFC split, and the focused other patch for improving the diags. Mixing the two is bad practice.

https://github.com/llvm/llvm-project/pull/201044