Support int-to-long conversions in the optimizing compiler.

- Add support for the int-to-float Dex instruction in the
  optimizing compiler.
- Add a HTypeConversion node type for control-flow graphs.
- Generate x86, x86-64 and ARM (but not ARM64) code for
  int-to-float HTypeConversion nodes.
- Add a 64-bit "Move doubleword to quadword with
  sign-extension" (MOVSXD) instruction to the x86-64
  assembler.
- Add related tests to test/422-type-conversion.

Change-Id: Ieb8ec5380f9c411857119c79aa8d0728fd10f780
diff --git a/compiler/utils/x86_64/assembler_x86_64.cc b/compiler/utils/x86_64/assembler_x86_64.cc
index 2e951dd..5b70658 100644
--- a/compiler/utils/x86_64/assembler_x86_64.cc
+++ b/compiler/utils/x86_64/assembler_x86_64.cc
@@ -351,6 +351,22 @@
 }
 
 
+void X86_64Assembler::movsxd(CpuRegister dst, CpuRegister src) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitRex64(dst);
+  EmitUint8(0x63);
+  EmitRegisterOperand(dst.LowBits(), src.LowBits());
+}
+
+
+void X86_64Assembler::movsxd(CpuRegister dst, const Address& src) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitRex64(dst);
+  EmitUint8(0x63);
+  EmitOperand(dst.LowBits(), src);
+}
+
+
 void X86_64Assembler::movd(XmmRegister dst, CpuRegister src) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0x66);
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index 5b16f08..ed80e44 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -300,6 +300,9 @@
   void movss(const Address& dst, XmmRegister src);
   void movss(XmmRegister dst, XmmRegister src);
 
+  void movsxd(CpuRegister dst, CpuRegister src);
+  void movsxd(CpuRegister dst, const Address& src);
+
   void movd(XmmRegister dst, CpuRegister src);
   void movd(CpuRegister dst, XmmRegister src);