[clang] [RISCV] Add canonical ISA string as Module metadata in IR. (PR #80760)

[Jessica Clarke via cfe-commits]

jrtc27 wrote:

That's fair. I just imagine this is going to result in people forgetting about the underlying issue and adding their own patchwork fixes to work around it in their targets, so it would be a nice motivation to fix it properly.

https://github.com/llvm/llvm-project/pull/80760