Move image_classes_ to CompilerOptions.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: Ifb30e071d7b39ae939fc3f83d7eba82fd077c7e8
diff --git a/dex2oat/linker/image_test.h b/dex2oat/linker/image_test.h
index 12ecd3a..2acdf25 100644
--- a/dex2oat/linker/image_test.h
+++ b/dex2oat/linker/image_test.h
@@ -426,9 +426,6 @@
     image_file_sizes.push_back(file->GetLength());
   }
 
-  ASSERT_TRUE(compiler_driver_->GetImageClasses() != nullptr);
-  HashSet<std::string> image_classes(*compiler_driver_->GetImageClasses());
-
   // Need to delete the compiler since it has worker threads which are attached to runtime.
   compiler_driver_.reset();
 
@@ -469,6 +466,7 @@
 
   // We loaded the runtime with an explicit image, so it must exist.
   ASSERT_EQ(heap->GetBootImageSpaces().size(), image_file_sizes.size());
+  const HashSet<std::string>& image_classes = compiler_options_->GetImageClasses();
   for (size_t i = 0; i < helper.dex_file_locations.size(); ++i) {
     std::unique_ptr<const DexFile> dex(
         LoadExpectSingleDexFile(helper.dex_file_locations[i].c_str()));