[clang] [llvm] Reapply "runtimes: Pass CMAKE_SYSTEM_NAME based on target triple" (#205133) (PR #208496)

[Matt Arsenault via cfe-commits]

arsenm wrote:

Yes, https://github.com/llvm/llvm-project/pull/225379 will replace the mechanism here and then this needs to be reworked to use it.

See also https://discourse.llvm.org/t/rfc-fixing-cmake-system-name-in-cross-compiled-runtimes-builds/91897

https://github.com/llvm/llvm-project/pull/208496