[llvm] [RISCV] Move VMV0 elimination past machine SSA opts (PR #126850)

[Philip Reames via llvm-commits]

preames wrote:

> Thanks for the quick response. Would you mind rolling back per https://llvm.org/docs/DeveloperPolicy.html#patch-reversion-policy as this breaks one of our internal toolchains. Otherwise we will soon be in a situation where crucial build jobs become non-functional, and we'd really like to avoid that.

Waiting a week to report a problem, and then asking for an immediate revert instead of a prompt fix is not a reasonable.  Luke, please do revert if the fix turns out to be non-trivial, but up to you to make a judgement call here.    

https://github.com/llvm/llvm-project/pull/126850