Make all pointers to TargetRegisterClass const since they are all pointers to static data that should not be modified.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151134 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 1231afc..7180b22 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1698,7 +1698,7 @@
 
     // Arguments stored in registers.
     if (VA.isRegLoc()) {
-      TargetRegisterClass *RC;
+      const TargetRegisterClass *RC;
       EVT ValVT = VA.getValVT();
 
       switch (ValVT.getSimpleVT().SimpleTy) {