[llvm] [clang] [libcxx] [mlir] [compiler-rt] [sanitizer] Skip /include/c++/ from summary (PR #78534)

[via cfe-commits]

zmodem wrote:

This broke lit tests on Darwin, see https://green.lab.llvm.org/green/job/clang-stage1-RA/37026/execution/node/39/log/?consoleFull and https://bugs.chromium.org/p/chromium/issues/detail?id=1519812

I've reverted in 4619147911c2a955bb605618bc518b45da994a81 for now.

https://github.com/llvm/llvm-project/pull/78534