Add MachineBasicBlock::getName, and use it in place of getBasicBlock()->getName.

Fix debug code that assumes getBasicBlock never returns NULL.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89428 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index bbfc82b..56a9c56 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -136,7 +136,7 @@
 
   for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
        mbbi != mbbe; ++mbbi) {
-    OS << ((Value*)mbbi->getBasicBlock())->getName() << ":\n";
+    OS << mbbi->getName() << ":\n";
     for (MachineBasicBlock::iterator mii = mbbi->begin(),
            mie = mbbi->end(); mii != mie; ++mii) {
       OS << getInstructionIndex(mii) << '\t' << *mii;
@@ -658,7 +658,7 @@
     MachineBasicBlock *MBB = MBBI;
     // Track the index of the current machine instr.
     SlotIndex MIIndex = getMBBStartIdx(MBB);
-    DEBUG(errs() << ((Value*)MBB->getBasicBlock())->getName() << ":\n");
+    DEBUG(errs() << MBB->getName() << ":\n");
 
     MachineBasicBlock::iterator MI = MBB->begin(), miEnd = MBB->end();