Add support for int-to-byte in the optimizing compiler.

- Add support for the int-to-byte Dex instruction in the
  optimizing compiler.
- Implement the ARM and Thumb-2 SBFX instructions.
- Generate x86, x86-64 and ARM (but not ARM64) code for
  char to byte, short to byte and int to byte
  HTypeConversion nodes.
- Add related tests to test/422-type-conversion.

Change-Id: Ic8b8911b90d4b5281fad15bcee96bc3ee85dc577
diff --git a/compiler/utils/arm/assembler_arm32.h b/compiler/utils/arm/assembler_arm32.h
index dbabb99..b582e9e 100644
--- a/compiler/utils/arm/assembler_arm32.h
+++ b/compiler/utils/arm/assembler_arm32.h
@@ -96,6 +96,8 @@
   void sdiv(Register rd, Register rn, Register rm, Condition cond = AL) OVERRIDE;
   void udiv(Register rd, Register rn, Register rm, Condition cond = AL) OVERRIDE;
 
+  void sbfx(Register rd, Register rn, uint32_t lsb, uint32_t width, Condition cond = AL) OVERRIDE;
+
   // Load/store instructions.
   void ldr(Register rd, const Address& ad, Condition cond = AL) OVERRIDE;
   void str(Register rd, const Address& ad, Condition cond = AL) OVERRIDE;