[clang] [llvm] [Clang] Add env var for nvptx-arch/amdgpu-arch timeout (PR #102521)

[Joel E. Denny via cfe-commits]

jdenny-ornl wrote:

> Also, just be aware that if you set this, it will apply to everything. So if you had a particularly long link job, probably would be a good idea to make it wait forever.

Not sure I understand.  grep found 2 uses of executeToolChainProgram: calling amdgpu-arch and nvptx-arch.  Did I miss a use?

https://github.com/llvm/llvm-project/pull/102521