[llvm] [AArch64] Don't try to vectorize fixed point to fp narrowing conversion (PR #130665)

[David Green via llvm-commits]

davemgreen wrote:

There will be a lot of test cases that need updating. We should attempt to limit the damage this does, and I don't believe the default expansion is very efficient for unsigned operations.

https://github.com/llvm/llvm-project/pull/130665