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/modifiers.h b/src/modifiers.h
index ee2d4ff..78ba140 100644
--- a/src/modifiers.h
+++ b/src/modifiers.h
@@ -17,6 +17,8 @@
 #ifndef ART_SRC_MODIFIERS_H_
 #define ART_SRC_MODIFIERS_H_
 
+#include <stdint.h>
+
 static const uint32_t kAccPublic = 0x0001;  // class, field, method, ic
 static const uint32_t kAccPrivate = 0x0002;  // field, method, ic
 static const uint32_t kAccProtected = 0x0004;  // field, method, ic