[llvm] AMDGPU: Fix using wrong memory type for non-image resource intrinsics (PR #94911)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> > An 8 x i16 raw load
> 
> Is that a typo? The patch only touches 8 x **f16**.

The test is for f16, but it's any 16-bit element type. The test is mostly filler because I'm fixing a bunch of these in a later patch 

https://github.com/llvm/llvm-project/pull/94911