[llvm] [RISCV] Disable constant hoisting for mul by one more/less than a pow… (PR #67385)

[Philip Reames via llvm-commits]

https://github.com/preames approved this pull request.

LGTM

The negative power of two question in review is a good one, and would make a reasonable follow up patch if desired.

https://github.com/llvm/llvm-project/pull/67385