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

[Cyndy Ishida via cfe-commits]

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

Looks like that was previously attempted by @ldionne  in https://github.com/llvm/llvm-project/pull/75841 

The problem was appending `/Library/Frameworks` to the sysroot. I'll try rebasing that. 

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