[llvm] [LLVM] Make -use-constant-fp-for-fixed-length-splat the default. (PR #193264)

[Paul Walker via llvm-commits]

paulwalker-arm wrote:

I've created https://github.com/llvm/llvm-project/pull/193738 to fix https://lab.llvm.org/buildbot/#/builders/117/builds/18799.

https://github.com/llvm/llvm-project/pull/193264