[optimizing compiler] Add support for volatile

- for backends: arm, x86, x86_64
- added necessary instructions to assemblies
- clean up code gen for field set/get
- fixed InstructionDataEquals for some instructions
- fixed comments in compiler_enums

* 003-opcode test verifies basic volatile functionality

Change-Id: I144393efa312dfb2c332cb84056b00edffee338a
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index f0353f6..f8c0043 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -443,6 +443,27 @@
 }
 
 
+void X86Assembler::psrlq(XmmRegister reg, const Immediate& shift_count) {
+  DCHECK(shift_count.is_uint8());
+
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x66);
+  EmitUint8(0x0F);
+  EmitUint8(0x73);
+  EmitXmmRegisterOperand(2, reg);
+  EmitUint8(shift_count.value());
+}
+
+
+void X86Assembler::punpckldq(XmmRegister dst, XmmRegister src) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x66);
+  EmitUint8(0x0F);
+  EmitUint8(0x62);
+  EmitXmmRegisterOperand(dst, src);
+}
+
+
 void X86Assembler::addsd(XmmRegister dst, XmmRegister src) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xF2);