Add #includes that were eliminated from headers


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4380 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp b/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
index 9e9e5dd..c569a29 100644
--- a/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
+++ b/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
@@ -6,6 +6,7 @@
 
 #include "llvm/CodeGen/RegisterAllocation.h"
 #include "llvm/CodeGen/RegAllocCommon.h"
+#include "llvm/CodeGen/IGNode.h"
 #include "llvm/CodeGen/PhyRegAlloc.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrAnnot.h"