[llvm] LoopVectorize: run verifyFunction once (PR #91470)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

Oh no, if the data doesn't show up in the LLVM Compile Time Tracker, then I'm afraid I don't have any reliable data: I'm on a MacBook, and there doesn't seem to be any reliable way to get performance benchmarking data without perf-tools or callgrind. The patch is very much a blind experiment, as I noticed wasteful verification in Instruments.app when building CTMark. I posted the patch because the downside is quite minimal.

https://github.com/llvm/llvm-project/pull/91470