Remove #include "oat_file.h" from class_linker.h .

Refactor the OatClass and OatMethod related functions from
ClassLinker to OatFile and ArtMethod, respectively. Refactor
the remaining ClassLinker dependencies on OatFile to break
the #include dependency and reduce incremental build times.

Test: m test-art-host
Change-Id: Iebc5b9f81b48fbcf79821cc827a5d7c4a0261bf6
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index df0dca0..3d74af4 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -143,6 +143,7 @@
 #include "trace.h"
 #include "transaction.h"
 #include "utils.h"
+#include "vdex_file.h"
 #include "verifier/method_verifier.h"
 #include "well_known_classes.h"