Subzero: Refactor x86 register representation to actively use aliases.

src/IceTargetLowering.h

Index: src/IceTargetLowering.h
diff --git a/src/IceTargetLowering.h b/src/IceTargetLowering.h
index f5182251c38a09639c07e72d3fe1be59e9731a86..aff423c44428e5d1ad489b370cba5564b13d290a 100644
--- a/src/IceTargetLowering.h
+++ b/src/IceTargetLowering.h
@@ -234,7 +234,8 @@ public:
 
   virtual llvm::SmallBitVector getRegisterSet(RegSetMask Include,
                                               RegSetMask Exclude) const = 0;
-  virtual const llvm::SmallBitVector &getRegisterSetForType(Type Ty) const = 0;
+  virtual const llvm::SmallBitVector &
+  getRegistersForVariable(const Variable *Var) const = 0;
   virtual const llvm::SmallBitVector &getAliasesForRegister(SizeT) const = 0;
 
   void regAlloc(RegAllocKind Kind);