Revert "[NFC][PowerPC] Remove the repeated definition for some InstAl…

…ias of mtspr/mfspr"

This reverts commit 46126a3.
Some test cases failed.

llvm/lib/Target/PowerPC/PPCInstrInfo.td

@@ -4627,8 +4627,19 @@ foreach SPRG = 4-7 in {
 
 def : InstAlias<"mtasr $RS", (MTSPR 280, gprc:$RS)>;
 
+def : InstAlias<"mfdec $RT", (MFSPR gprc:$RT, 22)>;
+def : InstAlias<"mtdec $RT", (MTSPR 22, gprc:$RT)>;
+
 def : InstAlias<"mfpvr $RT", (MFSPR gprc:$RT, 287)>;
 
+def : InstAlias<"mfsdr1 $RT", (MFSPR gprc:$RT, 25)>;
+def : InstAlias<"mtsdr1 $RT", (MTSPR 25, gprc:$RT)>;
+
+def : InstAlias<"mfsrr0 $RT", (MFSPR gprc:$RT, 26)>;
+def : InstAlias<"mfsrr1 $RT", (MFSPR gprc:$RT, 27)>;
+def : InstAlias<"mtsrr0 $RT", (MTSPR 26, gprc:$RT)>;
+def : InstAlias<"mtsrr1 $RT", (MTSPR 27, gprc:$RT)>;
+
 def : InstAlias<"tlbie $RB", (TLBIE R0, gprc:$RB)>;
 
 def : InstAlias<"tlbrehi $RS, $A", (TLBRE2 gprc:$RS, gprc:$A, 0)>,