[clang] Fix preprocessed block comment newline on windows containing extra carriage return (PR #205084)

[Aaron Ballman via cfe-commits]

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@@ -0,0 +1,6 @@
+// REQUIRES: system-windows
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AaronBallman wrote:

Do we really want this to be Windows-only behavior? I would assume that the platform doesn't matter, it's the file contents that matter, and so we'd expect the same behavior on all platforms?

https://github.com/llvm/llvm-project/pull/205084