[clang] Remove Linux search paths on Windows (PR #113628)

[David Salinas via cfe-commits]

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@@ -6440,7 +6440,8 @@ const ToolChain &Driver::getToolChain(const ArgList &Args,
       TC = std::make_unique<toolchains::NVPTXToolChain>(*this, Target, Args);
       break;
     case llvm::Triple::AMDHSA:
-      TC = std::make_unique<toolchains::ROCMToolChain>(*this, Target, Args);
+      TC = std::make_unique<toolchains::ROCMToolChain>(*this, Target, Args,
+                                                       Target.isOSWindows());
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david-salinas wrote:

The reason we need to pass this is primarily/solely because when we create the Offloading Device ToolChain (in "Driver::getOffloadingDeviceToolChain()", we pass the Device's triple to the toolchain constructor as the target triple; which as you mentioned will not be Windows.  Then the Device side toolchain, has it's own RocmInstallationDetector, which will add the linux paths.  And I need a way to tell the RocmInstallationDetector, on the device side ToolChain, that the Host TC is actually Windows.  

I tried a couple of different approaches to handle this case, but this is the least intrusive so far.  The RocmInstallationDetector sets the search paths in its constructor, and all of the ToolChains that have a Rocm Detector call its constructor in their respective initialize list in their constructors.  I need a way to tell that detector instance (for a device side toolchain) that it's Host ToolChain is windows and to not add the linux search paths.

https://github.com/llvm/llvm-project/pull/113628