emitIAS for push -- simplify push since it's not used for args passing anymore

src/assembler_ia32.h

 // 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.
 //
 //===- subzero/src/assembler_ia32.h - Assembler for x86-32 ----------------===//
 //
 //                        The Subzero Code Generator
 //
@@ skipping 375 matching lines @@
    * Emit Machine Instructions.
    */
   void call(GPRRegister reg);
   void call(const Address &address);
   void call(Label *label);
   void call(const ConstantRelocatable *label);
 
   static const intptr_t kCallExternalLabelSize = 5;
 
   void pushl(GPRRegister reg);
-  void pushl(const Address &address);
-  void pushl(const Immediate &imm);
 
   void popl(GPRRegister reg);
   void popl(const Address &address);
 
   void pushal();
   void popal();
 
   void setcc(CondX86::BrCond condition, ByteRegister dst);
 
   void movl(GPRRegister dst, const Immediate &src);
@@ skipping 381 matching lines @@
 inline void AssemblerX86::EmitFixup(AssemblerFixup *fixup) {
   buffer_.EmitFixup(fixup);
 }
 
 inline void AssemblerX86::EmitOperandSizeOverride() { EmitUint8(0x66); }
 
 } // end of namespace x86
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ASSEMBLER_IA32_H_