Add support for long-to-double in the optimizing compiler.

- Add support for the long-to-double Dex instruction in the
  optimizing compiler.
- Enable requests of temporary FPU (double) registers during
  code generation.
- Fix art::x86::X86Assembler::LoadLongConstant and extend
  it to int64_t values.
- Have art::x86_64::X86_64Assembler::cvtsi2sd work with
  64-bit operands.
- Generate x86, x86-64 and ARM (but not ARM64) code for
  long to double HTypeConversion nodes.
- Add related tests to test/422-type-conversion.

Change-Id: Ie73d9e5e25bd2e15f585c371e8fc2dcb83438ccd
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 6ea66a5..0d82487 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -42,8 +42,6 @@
 
  private:
   const int32_t value_;
-
-  DISALLOW_COPY_AND_ASSIGN(Immediate);
 };
 
 
@@ -441,6 +439,7 @@
 
   void AddImmediate(Register reg, const Immediate& imm);
 
+  void LoadLongConstant(XmmRegister dst, int64_t value);
   void LoadDoubleConstant(XmmRegister dst, double value);
 
   void DoubleNegate(XmmRegister d);