Directory restructuring of object.h

Break object.h into constituent files.
Reduce number of #includes in other GC header files.
Introduce -inl.h files to avoid mirror files #include-ing each other.
Check invariants of verifier RegTypes for all constructors.

Change-Id: Iecf1171c02910ac152d52947330ef456df4043bc
diff --git a/src/compiler_llvm/runtime_support_builder_thumb2.cc b/src/compiler_llvm/runtime_support_builder_thumb2.cc
index 3299afe..c18ae83 100644
--- a/src/compiler_llvm/runtime_support_builder_thumb2.cc
+++ b/src/compiler_llvm/runtime_support_builder_thumb2.cc
@@ -17,8 +17,8 @@
 #include "runtime_support_builder_thumb2.h"
 
 #include "ir_builder.h"
+#include "mirror/object.h"
 #include "monitor.h"
-#include "object.h"
 #include "thread.h"
 #include "utils_llvm.h"