Eliminate the IS_PHI_DEF flag and VNInfo::setIsPHIDef().

A value number is a PHI def if and only if it begins at a block
boundary. This can be derived from the def slot, a separate flag is not
necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160893 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRangeCalc.cpp b/lib/CodeGen/LiveRangeCalc.cpp
index 9384075..d828f25 100644
--- a/lib/CodeGen/LiveRangeCalc.cpp
+++ b/lib/CodeGen/LiveRangeCalc.cpp
@@ -54,8 +54,7 @@
         .getRegSlot(I.getOperand().isEarlyClobber());
 
     // Create the def in LI. This may find an existing def.
-    VNInfo *VNI = LI->createDeadDef(Idx, *Alloc);
-    VNI->setIsPHIDef(MI->isPHI());
+    LI->createDeadDef(Idx, *Alloc);
   }
 }
 
@@ -320,7 +319,6 @@
         SlotIndex Start, End;
         tie(Start, End) = Indexes->getMBBRange(MBB);
         VNInfo *VNI = I->LI->getNextValue(Start, *Alloc);
-        VNI->setIsPHIDef(true);
         I->Value = VNI;
         // This block is done, we know the final value.
         I->DomNode = 0;