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/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 79638b3..d7069ca 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -516,6 +516,7 @@
   M(Sub, BinaryOperation)                                               \
   M(SuspendCheck, Instruction)                                          \
   M(Temporary, Instruction)                                             \
+  M(TypeConversion, Instruction)                                        \
 
 #define FOR_EACH_INSTRUCTION(M)                                         \
   FOR_EACH_CONCRETE_INSTRUCTION(M)                                      \
@@ -1761,6 +1762,28 @@
   DISALLOW_COPY_AND_ASSIGN(HNot);
 };
 
+class HTypeConversion : public HExpression<1> {
+ public:
+  // Instantiate a type conversion of `input` to `result_type`.
+  HTypeConversion(Primitive::Type result_type, HInstruction* input)
+      : HExpression(result_type, SideEffects::None()) {
+    SetRawInputAt(0, input);
+    DCHECK_NE(input->GetType(), result_type);
+  }
+
+  HInstruction* GetInput() const { return InputAt(0); }
+  Primitive::Type GetInputType() const { return GetInput()->GetType(); }
+  Primitive::Type GetResultType() const { return GetType(); }
+
+  bool CanBeMoved() const OVERRIDE { return true; }
+  bool InstructionDataEquals(HInstruction* /* other */) const OVERRIDE { return true; }
+
+  DECLARE_INSTRUCTION(TypeConversion);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HTypeConversion);
+};
+
 class HPhi : public HInstruction {
  public:
   HPhi(ArenaAllocator* arena, uint32_t reg_number, size_t number_of_inputs, Primitive::Type type)