Smarter image layout

Put strings in the dex file that resolves them.

Depth first traversal with overrides for class and dex cache. The
work list keeps track of what oat_index with each pushed item. This
means the static fields of a class will usually be in the same image.

Added layout test to image_test to make sure things are somewhat
reasonably attributed.

Bug: 28640955

Test: test-art-host

(cherry picked from commit 4e9c4e746617bad6a012d799d2f5cf9e01d24ea2)

Change-Id: I67a536c33aeed603b252d8e0f75622c9efbf2559
diff --git a/compiler/common_compiler_test.cc b/compiler/common_compiler_test.cc
index 06a39b2..2af4d72 100644
--- a/compiler/common_compiler_test.cc
+++ b/compiler/common_compiler_test.cc
@@ -226,6 +226,7 @@
   method_inliner_map_.reset();
   verification_results_.reset();
   compiler_options_.reset();
+  image_reservation_.reset();
 
   CommonRuntimeTest::TearDown();
 }