Move ArtField to native

Add linear alloc. Moved ArtField to be native object. Changed image
writer to put ArtFields after the mirror section.

Savings:
2MB on low ram devices
4MB on normal devices

Total PSS measurements before (normal N5, 95s after shell start):
Image size: 7729152 bytes
23112 kB: .NonMoving
23212 kB: .NonMoving
22868 kB: .NonMoving
23072 kB: .NonMoving
22836 kB: .NonMoving
19618 kB: .Zygote
19850 kB: .Zygote
19623 kB: .Zygote
19924 kB: .Zygote
19612 kB: .Zygote
Avg: 42745.4 kB

After:
Image size: 7462912 bytes
17440 kB: .NonMoving
16776 kB: .NonMoving
16804 kB: .NonMoving
17812 kB: .NonMoving
16820 kB: .NonMoving
18788 kB: .Zygote
18856 kB: .Zygote
19064 kB: .Zygote
18841 kB: .Zygote
18629 kB: .Zygote
3499 kB: .LinearAlloc
3408 kB: .LinearAlloc
3424 kB: .LinearAlloc
3600 kB: .LinearAlloc
3436 kB: .LinearAlloc
Avg: 39439.4 kB

No reflection performance changes.

Bug: 19264997
Bug: 17643507

Change-Id: I10c73a37913332080aeb978c7c94713bdfe4fe1c
diff --git a/runtime/utils.cc b/runtime/utils.cc
index 8a23ff7..f13da8b 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -25,10 +25,10 @@
 #include <unistd.h>
 #include <memory>
 
+#include "art_field-inl.h"
 #include "base/stl_util.h"
 #include "base/unix_file/fd_file.h"
 #include "dex_file-inl.h"
-#include "mirror/art_field-inl.h"
 #include "mirror/art_method-inl.h"
 #include "mirror/class-inl.h"
 #include "mirror/class_loader.h"
@@ -364,7 +364,7 @@
   return result;
 }
 
-std::string PrettyField(mirror::ArtField* f, bool with_type) {
+std::string PrettyField(ArtField* f, bool with_type) {
   if (f == NULL) {
     return "null";
   }