Subzero: Use llvm::ilist<> for PhiList and AssignList.

src/IceDefs.h

Index: src/IceDefs.h
diff --git a/src/IceDefs.h b/src/IceDefs.h
index 133b56b9714d57d4668e603390670c08fe0357ee..4160fec4abdec0f496696c9544b4c7a4ef84ae3c 100644
--- a/src/IceDefs.h
+++ b/src/IceDefs.h
@@ -60,10 +60,11 @@ class VariablesMetadata;
 // http://llvm.org/docs/ProgrammersManual.html#picking-the-right-data-structure-for-a-task
 typedef std::string IceString;
 typedef llvm::ilist<Inst> InstList;
-typedef std::list<InstAssign *> AssignList;
-typedef std::list<InstPhi *> PhiList;
+// Ideally PhiList would be llvm::ilist<InstPhi>, and similar for
+// AssignList, but this runs into issues with SFINAE.
+typedef InstList PhiList;
+typedef InstList AssignList;
 typedef std::vector<Variable *> VarList;
-typedef std::vector<Operand *> OperandList;
 typedef std::vector<CfgNode *> NodeList;
 typedef std::vector<Constant *> ConstantList;