fix constness warnings

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109224 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCBranchSelector.cpp b/lib/Target/PowerPC/PPCBranchSelector.cpp
index ab251e6..8c427a1 100644
--- a/lib/Target/PowerPC/PPCBranchSelector.cpp
+++ b/lib/Target/PowerPC/PPCBranchSelector.cpp
@@ -53,7 +53,8 @@
 }
 
 bool PPCBSel::runOnMachineFunction(MachineFunction &Fn) {
-  const PPCInstrInfo *TII = (PPCInstrInfo*)Fn.getTarget().getInstrInfo();
+  const PPCInstrInfo *TII =
+                static_cast<const PPCInstrInfo*>(Fn.getTarget().getInstrInfo());
   // Give the blocks of the function a dense, in-order, numbering.
   Fn.RenumberBlocks();
   BlockSizes.resize(Fn.getNumBlockIDs());