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

[Zeyi Xu via cfe-commits]

================
@@ -688,6 +686,26 @@ TEST(runToolOnCodeWithArgs, DiagnosticsColor) {
       {"-fcolor-diagnostics"}));
 }
 
+#if !defined(_WIN32)
----------------
zeyi2 wrote:

Added, thanks for reviewing.

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