Remove dex cache string from mirror::Class.

The compiled code does not need it anymore.

Test: test-art-host test-art-target
Change-Id: I71c08ce12d450ab2b2cd018330d42a8b8c9e3da2
diff --git a/runtime/interpreter/interpreter_common.h b/runtime/interpreter/interpreter_common.h
index c9a5b44..90310a5 100644
--- a/runtime/interpreter/interpreter_common.h
+++ b/runtime/interpreter/interpreter_common.h
@@ -254,7 +254,7 @@
   DCHECK_LT(string_idx.index_ % mirror::DexCache::kDexCacheStringCacheSize,
             declaring_class->GetDexFile().NumStringIds());
   ObjPtr<mirror::String> string_ptr =
-      mirror::StringDexCachePair::Lookup(declaring_class->GetDexCacheStrings(),
+      mirror::StringDexCachePair::Lookup(declaring_class->GetDexCache()->GetStrings(),
                                          string_idx.index_,
                                          mirror::DexCache::kDexCacheStringCacheSize).Read();
   if (UNLIKELY(string_ptr == nullptr)) {