[llvm] [llvm] [Triple] Add QNX Neutrino RTOS to llvm::Triple (PR #97417)

[Fangrui Song via llvm-commits]

MaskRay wrote:

Supporting a new OS is a huge undertaking. You will need a Discourse thread. https://discourse.llvm.org/t/new-clang-toolchain-acceptance-criteria/79233 may be useful. Note that Clang happily accepts target triples with components are not hard coded in Triple.h. The new enum members are added when you have custom in-tree logic like `if (getVendor() == XXX) do X`.

https://github.com/llvm/llvm-project/pull/97417