[llvm] [AMDGPU] Simplify S_WAIT_XCNT insertion. NFC. (PR #145682)

[Jay Foad via llvm-commits]

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@@ -866,7 +860,6 @@ void WaitcntBrackets::setScoreByInterval(RegInterval Interval,
       VgprUB = std::max(VgprUB, RegNo);
       VgprScores[CntTy][RegNo] = Score;
     } else {
-      assert(isSmemCounter(CntTy));
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jayfoad wrote:

Not needed because `getSgprScoresIdx` asserts anyway

https://github.com/llvm/llvm-project/pull/145682