patch 8.0.1026: GTK on-the-spot input has problems

Problem:    GTK on-the-spot input has problems. (Gerd Wachsmuth)
Solution:   Support over-the-spot. (Yukihiro Nakadaira, Ketn Takata, closes
            #1215)
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 128a918..32283c9 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -31,6 +31,7 @@
       \ 'history': [[0, 1, 100], [-1, 10001]],
       \ 'iminsert': [[0, 1], [-1, 3, 999]],
       \ 'imsearch': [[-1, 0, 1], [-2, 3, 999]],
+      \ 'imstyle': [[0, 1], [-1, 2, 999]],
       \ 'lines': [[2, 24], [-1, 0, 1]],
       \ 'linespace': [[0, 2, 4], ['']],
       \ 'numberwidth': [[1, 4, 8, 10], [-1, 0, 11]],