[llvm] [GlobalIsel][NFC] Fix LLT Propagation (PR #119587)

[Tim Gymnich via llvm-commits]

tgymnich wrote:

> Should we long-term deprecate those vector constructors that take bits?
@tschuett That would be one of the goals of the RFC. I'll create a follow up PR containing those changes.

https://github.com/llvm/llvm-project/pull/119587