[llvm] fix a bug of PPCMIPeepholes which description in issue 71030 (PR #85451)

[Amy Kwan via llvm-commits]

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@@ -2408,7 +2408,7 @@ defm SRW  : XForm_6r<31, 536, (outs gprc:$RA), (ins gprc:$RST, gprc:$RB),
                      [(set i32:$RA, (PPCsrl i32:$RST, i32:$RB))]>, ZExt32To64;
 defm SRAW : XForm_6rc<31, 792, (outs gprc:$RA), (ins gprc:$RST, gprc:$RB),
                       "sraw", "$RA, $RST, $RB", IIC_IntShift,
-                      [(set i32:$RA, (PPCsra i32:$RST, i32:$RB))]>, SExt32To64;
+                      [(set i32:$RA, (PPCsra i32:$RST, i32:$RB))]>;
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amy-kwan wrote:

May I ask why `SExt32To64` is removed from just `SRAW` and `SRAWI`?

https://github.com/llvm/llvm-project/pull/85451