[llvm] [AMDGPU] Legalize 64bit elements for BUILD_VECTOR on gfx942 (PR #145052)

[Janek van Oirschot via llvm-commits]

================
@@ -17497,6 +17536,95 @@ SDValue SITargetLowering::performSelectCombine(SDNode *N,
                          SelectLHS, SelectRHS);
 }
 
+SDValue
----------------
JanekvO wrote:

Let me know if this should be separated in another PR

https://github.com/llvm/llvm-project/pull/145052