Fix PHI handling in LiveIntervals::shrinkToUses().

We need to wait until we meet a PHIDef in its defining block before resurrecting
PHIKills in the predecessors.

This should unbreak the llvm-gcc-build-x86_64-darwin10-x-mingw32-x-armeabi bot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126905 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 92829b1..d326729 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -797,7 +797,7 @@
       (void)ExtVNI;
       assert(ExtVNI == VNI && "Unexpected existing value number");
       // Is this a PHIDef we haven't seen before?
-      if (!VNI->isPHIDef() || !UsedPHIs.insert(VNI))
+      if (!VNI->isPHIDef() || VNI->def != BlockStart || !UsedPHIs.insert(VNI))
         continue;
       // The PHI is live, make sure the predecessors are live-out.
       for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),