Merge "VectorImpl: print size on failure." into main

            // Fail instead of returning a pointer to storage that's not

            // editable. Otherwise we'd be editing the contents of a buffer

            // for which we're not the only owner, which is undefined behaviour.

            LOG_ALWAYS_FATAL_IF(editable == nullptr);

            LOG_ALWAYS_FATAL_IF(editable == nullptr, "size: %zu", sb->size());

            _do_copy(editable->data(), mStorage, mCount);

            release_storage();

            mStorage = editable->data();