[clang] [clang-tools-extra] [clang][AST][clang-tidy] Do not set a reduced traversal scope in ASTM… (PR #132725)

[kadir çetinkaya via cfe-commits]

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@@ -94,8 +94,6 @@ Improvements to clang-tidy
 - :program:`clang-tidy` no longer processes declarations from system headers
   by default, greatly improving performance. This behavior is disabled if the
   `SystemHeaders` option is enabled.
-  Note: this may lead to false negatives; downstream users may need to adjust
-  their checks to preserve existing behavior.
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kadircet wrote:

i think this still holds. the matching logic is still different than before. despite this version being more conservative, i think there is still value in having an explicit `SkipSystemHeaders` flag so that affected users can run with old behavior until code fixes are available for affected clang-tidy checks.

https://github.com/llvm/llvm-project/pull/132725