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/builder.h b/compiler/optimizing/builder.h
index eea762f..f25415b 100644
--- a/compiler/optimizing/builder.h
+++ b/compiler/optimizing/builder.h
@@ -116,6 +116,10 @@
   template<typename T> void If_21t(const Instruction& instruction, uint32_t dex_offset);
   template<typename T> void If_22t(const Instruction& instruction, uint32_t dex_offset);
 
+  void Conversion_12x(const Instruction& instruction,
+                      Primitive::Type input_type,
+                      Primitive::Type result_type);
+
   void BuildReturn(const Instruction& instruction, Primitive::Type type);
 
   // Builds an instance field access node and returns whether the instruction is supported.