[llvm] [HashRecognize] Make `LHSAux` null if it is dead (PR #207231)

[Piotr Fusik via llvm-commits]

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@@ -433,7 +479,6 @@ define i16 @crc16.be.tc8.zext.data(i8 %msg, i16 %checksum) {
 ; CHECK-NEXT:    Initial CRC: i16 %checksum
 ; CHECK-NEXT:    Generating polynomial: 258
 ; CHECK-NEXT:    Computed CRC: %crc.next = select i1 %check.sb, i16 %crc.shl, i16 %crc.xor
-; CHECK-NEXT:    Auxiliary data: i8 %msg
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pfusik wrote:

Why does a comment change here, yet the emitted code is unaffected?

https://github.com/llvm/llvm-project/pull/207231