[llvm] [VPlan] Use frozen combined condition in early exit first-active-lane (PR #223643)

[Luke Lau via llvm-commits]

lukel97 wrote:

I can't seem to push anything to GitHub.com, to either my fork or the upstream repository, which is preventing me from landing the fix. Will keep trying...

https://github.com/llvm/llvm-project/pull/223643