[clang] [Clang][Darwin] Centralize framework search paths for headers & libraries. (PR #118543)

[Louis Dionne via cfe-commits]

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@@ -339,13 +340,11 @@ void InitHeaderSearch::AddDefaultIncludePaths(
   if (triple.isOSDarwin()) {
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ldionne wrote:

FWIW I agree with your assessment @cyndyishida. I just did the exercise of picking up #75841 and we basically need to pass `-iframework` from the driver to the frontend, but if we limit ourselves to existing functionality in the driver that ends up putting the framework search paths before other system headers. I think that should be attempted as a separate patch that tries reviving #75841.

https://github.com/llvm/llvm-project/pull/118543