Object model changes to support 64bit.

Modify mirror objects so that references between them use an ObjectReference
value type rather than an Object* so that functionality to compress larger
references can be captured in the ObjectRefererence implementation.
ObjectReferences are 32bit and all other aspects of object layout remain as
they are currently.

Expand fields in objects holding pointers so they can hold 64bit pointers. Its
expected the size of these will come down by improving where we hold compiler
meta-data.
Stub out x86_64 architecture specific runtime implementation.
Modify OutputStream so that reads and writes are of unsigned quantities.
Make the use of portable or quick code more explicit.
Templatize AtomicInteger to support more than just int32_t as a type.
Add missing, and fix issues relating to, missing annotalysis information on the
mutator lock.
Refactor and share implementations for array copy between System and uses
elsewhere in the runtime.
Fix numerous 64bit build issues.

Change-Id: I1a5694c251a42c9eff71084dfdd4b51fff716822
diff --git a/runtime/dex_file-inl.h b/runtime/dex_file-inl.h
index 3b2135c..a459308 100644
--- a/runtime/dex_file-inl.h
+++ b/runtime/dex_file-inl.h
@@ -44,7 +44,7 @@
 inline const DexFile::TryItem* DexFile::GetTryItems(const CodeItem& code_item, uint32_t offset) {
   const uint16_t* insns_end_ = &code_item.insns_[code_item.insns_size_in_code_units_];
   return reinterpret_cast<const TryItem*>
-      (RoundUp(reinterpret_cast<uint32_t>(insns_end_), 4)) + offset;
+      (RoundUp(reinterpret_cast<uintptr_t>(insns_end_), 4)) + offset;
 }
 
 static inline bool DexFileStringEquals(const DexFile* df1, uint32_t sidx1,