[clang-tools-extra] [NFC][clang-tidy] Add type annotations to check_clang_tidy (PR #133140)

[Nicolas van Kempen via cfe-commits]

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@@ -71,12 +72,12 @@ def try_run(args, raise_error=True):
 
 # This class represents the appearance of a message prefix in a file.
 class MessagePrefix:
-    def __init__(self, label):
+    def __init__(self, label: str):
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nicovank wrote:

Good catch, thank you, I always forget those because MyPy doesn't flag it.

https://github.com/llvm/llvm-project/pull/133140