Import Dart's parallel move resolver.

And write a few tests while at it.

A parallel move resolver will be needed for performing multiple moves
that are conceptually parallel, for example moves at a block
exit that branches to a block with phi nodes.

Change-Id: Ib95b247b4fc3f2c2fcab3b8c8d032abbd6104cd7
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index be51232..f1b16a1 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -793,5 +793,13 @@
   LOG(FATAL) << "Unimplemented";
 }
 
+void LocationsBuilderARM::VisitParallelMove(HParallelMove* instruction) {
+  LOG(FATAL) << "Unimplemented";
+}
+
+void InstructionCodeGeneratorARM::VisitParallelMove(HParallelMove* instruction) {
+  LOG(FATAL) << "Unimplemented";
+}
+
 }  // namespace arm
 }  // namespace art