[llvm] [llvm-lit] Process ANSI color codes in test output when formatting (PR #106776)

[via llvm-commits]

dyung wrote:

Hi @hnrklssn, the test you added, escape-color.py seems to be failing on a Windows bot:

https://lab.llvm.org/buildbot/#/builders/46/builds/4703

Can you take a look and revert if you need time to investigate?

https://github.com/llvm/llvm-project/pull/106776