[clang-tools-extra] [clang-tidy] Reject malformed -std spellings in `check_clang_tidy.py`. NFC. (PR #195609)

[Baranov Victor via cfe-commits]

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@@ -460,11 +460,14 @@ def run(self) -> None:
 
 
 def expand_std(std: str) -> List[str]:
-    split_std, or_later, _ = std.partition("-or-later")
+    split_std, or_later, suffix = std.partition("-or-later")
 
     if not or_later:
         return [split_std]
 
+    if suffix:
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vbvictor wrote:

Can we add comment here that this is for error path so that clang will give warning

https://github.com/llvm/llvm-project/pull/195609