[llvm] [AMDGPU][True16] Legalize S16 for G_STORE/G_LOAD in GlobalISel when True16 is enabled (PR #176963)

[Domenic Nutile via llvm-commits]

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@@ -544,7 +544,7 @@ static bool loadStoreBitcastWorkaround(const LLT Ty) {
 
 static bool isLoadStoreLegal(const GCNSubtarget &ST, const LegalityQuery &Query) {
   const LLT Ty = Query.Types[0];
-  return isRegisterType(ST, Ty) && isLoadStoreSizeLegal(ST, Query) &&
+  return isRegisterClassType(ST, Ty) && isLoadStoreSizeLegal(ST, Query) &&
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saxlungs wrote:

I see now that some changes have been made to `isRegisterType` upstream that I think make this change not necessary to include. However, this is a TODO in here to eventually replace all calls to `isRegisterType` with `isRegisterClassType` anyway. So, I can remove this change if you think it should go into a separate PR or just leave it in. Let me know which you prefer

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