Subzero: Refactor x86 register definitions to use the alias mechanism.

src/IceAssemblerX8632.h

 //===- subzero/src/IceAssemblerX8632.h - Assembler for x86-32 ---*- C++ -*-===//
 //
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
@@ skipping 27 matching lines @@
 namespace X8632 {
 
 using Immediate = ::Ice::X86Internal::Immediate;
 using Label = ::Ice::X86Internal::Label;
 
 class AssemblerX8632 : public X86Internal::AssemblerX86Base<TargetX8632> {
   AssemblerX8632(const AssemblerX8632 &) = delete;
   AssemblerX8632 &operator=(const AssemblerX8632 &) = delete;
 
 public:
-  explicit AssemblerX8632(GlobalContext *Ctx, bool use_far_branches = false)
-      : X86Internal::AssemblerX86Base<TargetX8632>(Asm_X8632, Ctx,
+  explicit AssemblerX8632(bool use_far_branches = false)
+      : X86Internal::AssemblerX86Base<TargetX8632>(Asm_X8632,
                                                    use_far_branches) {}
   ~AssemblerX8632() override = default;
 
   static bool classof(const Assembler *Asm) {
     return Asm->getKind() == Asm_X8632;
   }
 };
 
 } // end of namespace X8632
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEASSEMBLERX8632_H