[llvm] [True16] Make loads into s16 legal in GlobalISel (PR #176963)

[Petar Avramovic via llvm-commits]

https://github.com/petar-avramovic commented:

Sorry, I missed this PR.
Should be able to make it work with -global-isel -new-reg-bank-select (after https://github.com/llvm/llvm-project/pull/171653 is merged)
First, need to see unmerge/merge change (or put in another PR) it is not clear to me why is it needed, can you explain?
Also which tests are affected by load/store change, think most are from merge/unmerge change.

https://github.com/llvm/llvm-project/pull/176963