[clang] [Tooling] Preserve backslashes in POSIX source paths (PR #207499)

[Aaron Ballman via cfe-commits]

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@@ -688,6 +686,26 @@ TEST(runToolOnCodeWithArgs, DiagnosticsColor) {
       {"-fcolor-diagnostics"}));
 }
 
+#if !defined(_WIN32)
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AaronBallman wrote:

Rather than only defining the test for non-Win32, would it make more sense to test that Win32 gets different expected results?

https://github.com/llvm/llvm-project/pull/207499