Handle ARM "ret void" and function alignment with proper padding.

src/assembler_ia32.h

 //===- subzero/src/assembler_ia32.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 334 matching lines @@
   }
   ~AssemblerX8632() override;
 
   static const bool kNearJump = true;
   static const bool kFarJump = false;
 
   void alignFunction() override;
 
   SizeT getBundleAlignLog2Bytes() const override { return 5; }
 
+  const char *getNonExecPadDirective() const override { return ".p2align"; }
+
   llvm::ArrayRef<uint8_t> getNonExecBundlePadding() const override {
     static const uint8_t Padding[] = {0xF4};
     return llvm::ArrayRef<uint8_t>(Padding, 1);
   }
 
   void padWithNop(intptr_t Padding) override {
     while (Padding > MAX_NOP_SIZE) {
       nop(MAX_NOP_SIZE);
       Padding -= MAX_NOP_SIZE;
     }
@@ skipping 516 matching lines @@
 inline void AssemblerX8632::EmitFixup(AssemblerFixup *fixup) {
   buffer_.EmitFixup(fixup);
 }
 
 inline void AssemblerX8632::EmitOperandSizeOverride() { EmitUint8(0x66); }
 
 } // end of namespace X8632
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ASSEMBLER_IA32_H