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

[Alexander Richardson via llvm-commits]

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@@ -1005,6 +1005,44 @@ def _executeShCmd(cmd, shenv, results, timeoutHelper):
     return exitCode
 
 
+def reFindLast(r, s):
+    matches = r.findall(s)
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arichardson wrote:

Can we do this without a regex in the common case, just with .rfind("\33["). And only if there is actually a match in the line check that it has the expected pattern (either with or without a regex).

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