[clang] [clang][flang][windows] Prefer user-provided library paths (-L) (PR #90758)

[Fangrui Song via cfe-commits]

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@@ -0,0 +1,7 @@
+// REQUIRES: system-windows
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MaskRay wrote:

Add tests to existing msvc-link.c instead of a new file. Specify `--target=` to avoid reliance on the default target triple and avoid the need of REQUIRES.

https://github.com/llvm/llvm-project/pull/90758