Header file clean up.

Remove runtime.h from object.h.
Move TypeStaticIf to its own header file to avoid bringing utils.h into
allocator.h.
Move Array::DataOffset into -inl.h as it now has a utils.h dependency.
Fix include issues arising from this.

Change-Id: I4605b1aa4ff5f8dc15706a0132e15df03c7c8ba0
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 5d04ca6..f5437a1 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -18,7 +18,7 @@
 
 #include "entrypoints/quick/quick_entrypoints.h"
 #include "gc/accounting/card_table.h"
-#include "mirror/array.h"
+#include "mirror/array-inl.h"
 #include "mirror/art_method.h"
 #include "mirror/class.h"
 #include "mirror/object_reference.h"