[clang] [llvm] [llvm][Triple] Add `Environment` members and parsing for glibc/musl parity. (PR #107664)

[Alex Rønne Petersen via cfe-commits]

alexrp wrote:

> Do you have interesting to add them to GCC? I guess we need to add config.sub/config.guess first.

I would like to see the changes mirrored there, and code-wise it doesn't seem like a lot of work to do so. But, frankly, the contribution process for GCC (and the GNU ecosystem more broadly) just seems too convoluted and time-consuming. :slightly_frowning_face: I'm only barely finding time to contribute to LLVM between my work on Zig as it is.

https://github.com/llvm/llvm-project/pull/107664