[llvm] [RISCV] Add option to disable ASM compress. (PR #131670)

[Sam Elliott via llvm-commits]

lenary wrote:

Why do you need this as an option? There is no explanation in the PR.

You can currently use `.option norvc`, and I'm working on a new option for an "exact" mode.

https://github.com/llvm/llvm-project/pull/131670