[llvm-branch-commits] [NFC][SpecialCaseList] Move most of implementation in cpp file (PR #167280)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/167280

This commit moves the `RegexMatcher`, `GlobMatcher`, `Matcher` and
`Section` classes into an anonymous namespace within
`SpecialCaseList.cpp`. These classes are implementation details of
`SpecialCaseList` and do not need to be exposed in the header.