[compiler-rt] [libcxx] CompilerRT: Normalize COMPILER_RT_DEFAULT_TARGET_TRIPLE (PR #89234)

[YunQiang Su via llvm-commits]

wzssyqa wrote:


> > libcxx/utils/ci/run-buildbot is also updated to use armv7m-none-unknown-eabi
> 
> This also looks suspicious, I'm expecting `unknown-none`, not `none-unknown`.

Sound reasonable. I will try to fix `Triple::normalize`.

https://github.com/llvm/llvm-project/pull/89234