[clang-tidy] check_clang_tidy.py: support CHECK-NOTES prefix

Summary:
Currently, there is two configured prefixes: `CHECK-FIXES` and `CHECK-MESSAGES`
`CHECK-MESSAGES` checks that there are no test output lines with `warning:|error:`, which are not explicitly handled in lit tests.
However there does not seem to be a nice way to enforce for all the `note:` to be checked.
This was useful for me when developing D36836.

Reviewers: alexfh, klimek, aaron.ballman, hokein

Reviewed By: alexfh, aaron.ballman

Subscribers: JonasToth, JDevlieghere, xazax.hun, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D36892

llvm-svn: 339437
3 files changed
tree: 7f2527b3fe86d4c6dfb5f4df39473b83e7611c26
  1. clang/
  2. clang-tools-extra/
  3. compiler-rt/
  4. debuginfo-tests/
  5. libclc/
  6. libcxx/
  7. libcxxabi/
  8. libunwind/
  9. lld/
  10. lldb/
  11. llgo/
  12. llvm/
  13. openmp/
  14. parallel-libs/
  15. polly/
  16. README.md
README.md

Low Level Virtual Machine (LLVM)

This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.