Add SplitEditor to SplitKit. This class will be used to edit live intervals and
rewrite instructions for live range splitting.

Still work in progress.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109469 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h
index a5599f6..87a9b2a 100644
--- a/lib/CodeGen/VirtRegMap.h
+++ b/lib/CodeGen/VirtRegMap.h
@@ -152,6 +152,11 @@
       MachineFunctionPass::getAnalysisUsage(AU);
     }
 
+    MachineFunction &getMachineFunction() const {
+      assert(MF && "getMachineFunction called before runOnMAchineFunction");
+      return *MF;
+    }
+
     void grow();
 
     /// @brief returns true if the specified virtual register is