[llvm] GlobalISel/Combiner: Fix building G_CONSTANT for fp extended LLT (PR #196397)

[Petar Avramovic via llvm-commits]

petar-avramovic wrote:

> G_TRUNC is one of the ones that maybe should be limited to integer types.

Oh no, I used ` f16 = G_TRUNC i32` as legal instruction on older targets. Any alternatives then?



https://github.com/llvm/llvm-project/pull/196397