Some optimizations for the array alloc path.

- Force Array::Alloc() to be inlined.
- Simplify the array size overflow check.
- Turn fill_usable into a template parameter.
- Remove a branch in Array::DataOffset() and avoid
  Primitive::ComponentSize(), which has a switch, in the array alloc
  path.
- Strength reductions in the array size computation by using component
  size shifts instead of component sizes. Store component size shift
  in the upper 16 bits of primitive_type field.
- Speedup: ~4% (3435->3284) in MemAllocTest on N4.

Bug: 9986565

Change-Id: I4b142ffac4ab8b5b915836f1660a949d6442344c
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index a9c4b4a..5729ad8 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -1422,7 +1422,7 @@
     return error;
   }
   *new_array = gRegistry->Add(mirror::Array::Alloc<true>(Thread::Current(), c, length,
-                                                         c->GetComponentSize(),
+                                                         c->GetComponentSizeShift(),
                                                          Runtime::Current()->GetHeap()->GetCurrentAllocator()));
   return JDWP::ERR_NONE;
 }