Split local live ranges.

A local live range is live in a single basic block. If such a range fails to
allocate, try to find a sub-range that would get a larger spill weight than its
interference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125764 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h
index b503f04..6f771b6 100644
--- a/lib/CodeGen/SplitKit.h
+++ b/lib/CodeGen/SplitKit.h
@@ -116,6 +116,9 @@
   /// new interval.
   void clear();
 
+  /// getParent - Return the last analyzed interval.
+  const LiveInterval &getParent() const { return *CurLI; }
+
   /// hasUses - Return true if MBB has any uses of CurLI.
   bool hasUses(const MachineBasicBlock *MBB) const {
     return UsingBlocks.lookup(MBB);