We can also run the linear scan register allocator on thumb.

Change-Id: I5d21b5cbcdd93ff36342111de4ebcaab172034dd
diff --git a/compiler/optimizing/register_allocator.h b/compiler/optimizing/register_allocator.h
index e35ff56..be1c7ec 100644
--- a/compiler/optimizing/register_allocator.h
+++ b/compiler/optimizing/register_allocator.h
@@ -66,7 +66,10 @@
 
   static bool CanAllocateRegistersFor(const HGraph& graph, InstructionSet instruction_set);
   static bool Supports(InstructionSet instruction_set) {
-    return instruction_set == kX86 || instruction_set == kArm || instruction_set == kX86_64;
+    return instruction_set == kX86
+        || instruction_set == kArm
+        || instruction_set == kX86_64
+        || instruction_set == kThumb2;
   }
 
   size_t GetNumberOfSpillSlots() const {