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

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

Change-Id: If1829549708d9c3473efaa641f7f0bcfa6080ae9
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 09e1b97..da51a37 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -1367,6 +1367,22 @@
       }
       break;
 
+    case Primitive::kPrimShort:
+      switch (input_type) {
+        case Primitive::kPrimByte:
+        case Primitive::kPrimInt:
+        case Primitive::kPrimChar:
+          // Processing a Dex `int-to-short' instruction.
+          locations->SetInAt(0, Location::RequiresRegister());
+          locations->SetOut(Location::RequiresRegister(), Location::kNoOutputOverlap);
+          break;
+
+        default:
+          LOG(FATAL) << "Unexpected type conversion from " << input_type
+                     << " to " << result_type;
+      }
+      break;
+
     case Primitive::kPrimInt:
       switch (input_type) {
         case Primitive::kPrimLong:
@@ -1461,6 +1477,21 @@
       }
       break;
 
+    case Primitive::kPrimShort:
+      switch (input_type) {
+        case Primitive::kPrimByte:
+        case Primitive::kPrimInt:
+        case Primitive::kPrimChar:
+          // Processing a Dex `int-to-short' instruction.
+          __ sbfx(out.As<Register>(), in.As<Register>(), 0, 16);
+          break;
+
+        default:
+          LOG(FATAL) << "Unexpected type conversion from " << input_type
+                     << " to " << result_type;
+      }
+      break;
+
     case Primitive::kPrimInt:
       switch (input_type) {
         case Primitive::kPrimLong: