[clang] [llvm] [HIP][MacOS] Mach-O support and Darwin toolchain fixes (PR #183991)

[Joseph Huber via llvm-commits]

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@@ -1248,6 +1296,11 @@ void DarwinClang::addClangWarningOptions(ArgStringList &CC1Args) const {
   CC1Args.push_back("-Werror=undef-prefix");
 
   // For modern targets, promote certain warnings to errors.
+  // Lazily initialize the target if needed (e.g. when Darwin is used as
+  // a host toolchain for device offloading).
+  ensureTargetInitialized();
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jhuber6 wrote:

I'm not overly familiar with Darwin, but why does the target need to be initialized and why does offloading change it?

https://github.com/llvm/llvm-project/pull/183991