Tidy up a few more uses of MF.getFunction()->getName().

Based on CR feedback from r162301 and Craig Topper's refactoring in r162347
here are a few other places that could use the same API (& in one instance drop
a Function.h dependency).

llvm-svn: 162367

llvm/lib/CodeGen/StackSlotColoring.cpp

@@ -390,8 +390,7 @@ bool StackSlotColoring::RemoveDeadStores(MachineBasicBlock* MBB) {
 bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
   DEBUG({
       dbgs() << "********** Stack Slot Coloring **********\n"
-             << "********** Function: "
-             << MF.getName() << '\n';
+             << "********** Function: " << MF.getName() << '\n';
     });
 
   MFI = MF.getFrameInfo();