Revert "Combine direct_methods_ and virtual_methods_ fields of mirror::Class"

This reverts commit 6286a97bea0f584342803a215550038852b24776.

Change-Id: I5b00f6d1350e9c587acd4b185367dc815ea707de
diff --git a/runtime/entrypoints/entrypoint_utils.cc b/runtime/entrypoints/entrypoint_utils.cc
index 915d9ab..87e29ae 100644
--- a/runtime/entrypoints/entrypoint_utils.cc
+++ b/runtime/entrypoints/entrypoint_utils.cc
@@ -306,13 +306,11 @@
       mirror::Method* interface_method = soa.Decode<mirror::Method*>(interface_method_jobj);
       ArtMethod* proxy_method = rcvr->GetClass()->FindVirtualMethodForInterface(
           interface_method->GetArtMethod(), sizeof(void*));
-      auto virtual_methods = proxy_class->GetVirtualMethodsSlice(sizeof(void*));
+      auto* virtual_methods = proxy_class->GetVirtualMethodsPtr();
       size_t num_virtuals = proxy_class->NumVirtualMethods();
       size_t method_size = ArtMethod::Size(sizeof(void*));
-      // Rely on the fact that the methods are contiguous to determine the index of the method in
-      // the slice.
       int throws_index = (reinterpret_cast<uintptr_t>(proxy_method) -
-          reinterpret_cast<uintptr_t>(&virtual_methods.At(0))) / method_size;
+          reinterpret_cast<uintptr_t>(virtual_methods)) / method_size;
       CHECK_LT(throws_index, static_cast<int>(num_virtuals));
       mirror::ObjectArray<mirror::Class>* declared_exceptions =
           proxy_class->GetThrows()->Get(throws_index);