[llvm] [GlobalIsel] Pust cast through build vector (PR #104634)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

Maybe the
https://github.com/llvm/llvm-project/blob/362142c4bb5cc657151f592e507f552d5b9f7dde/llvm/include/llvm/CodeGen/TargetLowering.h#L3056
get materialized.

https://github.com/llvm/llvm-project/pull/104634