[llvm] [LAA] Don't assume libcalls with output/input pointers can be vectorized (PR #108980)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

I intend to land this shortly as this alone is simply restricting a check (to avoid a known broken case). 

Possibly changing the existing behaviour is a separate issue (that can be handled in another PR).

https://github.com/llvm/llvm-project/pull/108980