First chunk of MachineInstr bundle support.
1. Added opcode BUNDLE
2. Taught MachineInstr class to deal with bundled MIs
3. Changed MachineBasicBlock iterator to skip over bundled MIs; added an iterator to walk all the MIs
4. Taught MachineBasicBlock methods about bundled MIs

llvm-svn: 145975
diff --git a/llvm/lib/CodeGen/MachineLICM.cpp b/llvm/lib/CodeGen/MachineLICM.cpp
index e5e8c51..f88b730 100644
--- a/llvm/lib/CodeGen/MachineLICM.cpp
+++ b/llvm/lib/CodeGen/MachineLICM.cpp
@@ -1141,8 +1141,9 @@
   assert(NewMIs.size() == 2 &&
          "Unfolded a load into multiple instructions!");
   MachineBasicBlock *MBB = MI->getParent();
-  MBB->insert(MI, NewMIs[0]);
-  MBB->insert(MI, NewMIs[1]);
+  MachineBasicBlock::iterator Pos = MI;
+  MBB->insert(Pos, NewMIs[0]);
+  MBB->insert(Pos, NewMIs[1]);
   // If unfolding produced a load that wasn't loop-invariant or profitable to
   // hoist, discard the new instructions and bail.
   if (!IsLoopInvariantInst(*NewMIs[0]) || !IsProfitableToHoist(*NewMIs[0])) {