message: Use UnknownVendor rather than UnknownArch since they're in two different enums
  and we're switching on vendor and not arch.
diff: @@ -78,7 +78,7 @@ PlatformSP PlatformWindows::CreateInstance(bool force,
  create = true;
  break;
  - case llvm::Triple::UnknownArch:
  + case llvm::Triple::UnknownVendor:
  create = !arch->TripleVendorWasSpecified();
  break;
  