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/proxy_test.cc b/runtime/proxy_test.cc
index cb97049..a3156b4 100644
--- a/runtime/proxy_test.cc
+++ b/runtime/proxy_test.cc
@@ -17,8 +17,8 @@
 #include <jni.h>
 #include <vector>
 
+#include "art_field-inl.h"
 #include "common_compiler_test.h"
-#include "mirror/art_field-inl.h"
 #include "scoped_thread_state_change.h"
 
 namespace art {
@@ -165,14 +165,12 @@
   ASSERT_TRUE(proxyClass->IsProxyClass());
   ASSERT_TRUE(proxyClass->IsInitialized());
 
-  Handle<mirror::ObjectArray<mirror::ArtField>> instance_fields(
-      hs.NewHandle(proxyClass->GetIFields()));
-  EXPECT_TRUE(instance_fields.Get() == nullptr);
+  ArtField* instance_fields = proxyClass->GetIFields();
+  EXPECT_TRUE(instance_fields == nullptr);
 
-  Handle<mirror::ObjectArray<mirror::ArtField>> static_fields(
-      hs.NewHandle(proxyClass->GetSFields()));
-  ASSERT_TRUE(static_fields.Get() != nullptr);
-  ASSERT_EQ(2, static_fields->GetLength());
+  ArtField* static_fields = proxyClass->GetSFields();
+  ASSERT_TRUE(static_fields != nullptr);
+  ASSERT_EQ(2u, proxyClass->NumStaticFields());
 
   Handle<mirror::Class> interfacesFieldClass(
       hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Class;")));
@@ -182,21 +180,21 @@
   ASSERT_TRUE(throwsFieldClass.Get() != nullptr);
 
   // Test "Class[] interfaces" field.
-  MutableHandle<mirror::ArtField> fhandle = hs.NewHandle(static_fields->Get(0));
-  EXPECT_EQ("interfaces", std::string(fhandle->GetName()));
-  EXPECT_EQ("[Ljava/lang/Class;", std::string(fhandle->GetTypeDescriptor()));
-  EXPECT_EQ(interfacesFieldClass.Get(), fhandle->GetType<true>());
+  ArtField* field = &static_fields[0];
+  EXPECT_STREQ("interfaces", field->GetName());
+  EXPECT_STREQ("[Ljava/lang/Class;", field->GetTypeDescriptor());
+  EXPECT_EQ(interfacesFieldClass.Get(), field->GetType<true>());
   std::string temp;
-  EXPECT_EQ("L$Proxy1234;", std::string(fhandle->GetDeclaringClass()->GetDescriptor(&temp)));
-  EXPECT_FALSE(fhandle->IsPrimitiveType());
+  EXPECT_STREQ("L$Proxy1234;", field->GetDeclaringClass()->GetDescriptor(&temp));
+  EXPECT_FALSE(field->IsPrimitiveType());
 
   // Test "Class[][] throws" field.
-  fhandle.Assign(static_fields->Get(1));
-  EXPECT_EQ("throws", std::string(fhandle->GetName()));
-  EXPECT_EQ("[[Ljava/lang/Class;", std::string(fhandle->GetTypeDescriptor()));
-  EXPECT_EQ(throwsFieldClass.Get(), fhandle->GetType<true>());
-  EXPECT_EQ("L$Proxy1234;", std::string(fhandle->GetDeclaringClass()->GetDescriptor(&temp)));
-  EXPECT_FALSE(fhandle->IsPrimitiveType());
+  field = &static_fields[1];
+  EXPECT_STREQ("throws", field->GetName());
+  EXPECT_STREQ("[[Ljava/lang/Class;", field->GetTypeDescriptor());
+  EXPECT_EQ(throwsFieldClass.Get(), field->GetType<true>());
+  EXPECT_STREQ("L$Proxy1234;", field->GetDeclaringClass()->GetDescriptor(&temp));
+  EXPECT_FALSE(field->IsPrimitiveType());
 }
 
 }  // namespace art