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).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162367 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/ProcessImplicitDefs.cpp

@@ -137,8 +137,7 @@ void ProcessImplicitDefs::processImplicitDef(MachineInstr *MI) {
 bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &MF) {
 
   DEBUG(dbgs() << "********** PROCESS IMPLICIT DEFS **********\n"
-               << "********** Function: "
-               << ((Value*)MF.getFunction())->getName() << '\n');
+               << "********** Function: " << MF.getName() << '\n');
 
   bool Changed = false;