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/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index f20a714..dce3389 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -725,8 +725,8 @@
   // First, try to perform the bitcast by inserting a reg-reg copy.
   unsigned ResultReg = 0;
   if (SrcVT.getSimpleVT() == DstVT.getSimpleVT()) {
-    TargetRegisterClass* SrcClass = TLI.getRegClassFor(SrcVT);
-    TargetRegisterClass* DstClass = TLI.getRegClassFor(DstVT);
+    const TargetRegisterClass* SrcClass = TLI.getRegClassFor(SrcVT);
+    const TargetRegisterClass* DstClass = TLI.getRegClassFor(DstVT);
     // Don't attempt a cross-class copy. It will likely fail.
     if (SrcClass == DstClass) {
       ResultReg = createResultReg(DstClass);