Revert "Revert "Store resolved Strings for AOT code in .bss.""

Fixed oat_test to keep dex files alive. Fixed mips build.
Rewritten the .bss GC root visiting and added write barrier
to the artResolveStringFromCode().

Test: build aosp_mips-eng
Test: m ART_DEFAULT_GC_TYPE=SS test-art-target-host-gtest-oat_test
Test: Run ART test suite on host and Nexus 9.
Bug: 20323084
Bug: 30627598

This reverts commit 5f926055cb88089d8ca27243f35a9dfd89d981f0.

Change-Id: I07fa2278d82b8eb64964c9a4b66cb93726ccda6b
diff --git a/compiler/image_test.cc b/compiler/image_test.cc
index 4689c9d..9e94b9d 100644
--- a/compiler/image_test.cc
+++ b/compiler/image_test.cc
@@ -263,7 +263,10 @@
         oat_writer->PrepareLayout(driver, writer.get(), cur_dex_files, &patcher);
         size_t rodata_size = oat_writer->GetOatHeader().GetExecutableOffset();
         size_t text_size = oat_writer->GetOatSize() - rodata_size;
-        elf_writer->SetLoadedSectionSizes(rodata_size, text_size, oat_writer->GetBssSize());
+        elf_writer->PrepareDynamicSection(rodata_size,
+                                          text_size,
+                                          oat_writer->GetBssSize(),
+                                          oat_writer->GetBssRootsOffset());
 
         writer->UpdateOatFileLayout(i,
                                     elf_writer->GetLoadedSize(),