[llvm] [NVPTX] Add PRMT constant folding and cleanup usage of PRMT node (PR #148906)

[Alex MacLean via llvm-commits]

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@@ -5797,47 +5844,116 @@ static SDValue combineADDRSPACECAST(SDNode *N,
   return SDValue();
 }
 
+static APInt getPRMTSelector(APInt Selector, unsigned Mode) {
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AlexMaclean wrote:

Added

https://github.com/llvm/llvm-project/pull/148906