Move most of runtime/base to libartbase/base

Enforce the layering that code in runtime/base should not depend on
runtime by separating it into libartbase.  Some of the code in
runtime/base depends on the Runtime class, so it cannot be moved yet.
Also, some of the tests depend on CommonRuntimeTest, which itself needs
to be factored (in a subsequent CL).

Bug: 22322814
Test: make -j 50 checkbuild
      make -j 50 test-art-host

Change-Id: I8b096c1e2542f829eb456b4b057c71421b77d7e2
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 7a09391..3f4e841 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -21,6 +21,7 @@
 #include "art_field-inl.h"
 #include "art_method-inl.h"
 #include "base/logging.h"  // For VLOG.
+#include "base/utils.h"
 #include "class-inl.h"
 #include "class_ext.h"
 #include "class_linker-inl.h"
@@ -40,7 +41,6 @@
 #include "runtime.h"
 #include "thread.h"
 #include "throwable.h"
-#include "utils.h"
 #include "well_known_classes.h"
 
 namespace art {