patch 8.1.1855: another failing timer test

Problem:    Another failing timer test.
Solution:   Assert that timers are finished by the end of the test.  Rename
            test functions to make them easier to find.
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 7530bb9..32c22fa 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -323,20 +323,15 @@
       \ 'Test_exit_callback()',
       \ 'Test_exit_callback_interval()',
       \ 'Test_nb_basic()',
-      \ 'Test_oneshot()',
       \ 'Test_open_delay()',
       \ 'Test_out_cb()',
-      \ 'Test_paused()',
       \ 'Test_pipe_through_sort_all()',
       \ 'Test_pipe_through_sort_some()',
       \ 'Test_quoteplus()',
       \ 'Test_quotestar()',
       \ 'Test_raw_one_time_callback()',
       \ 'Test_reltime()',
-      \ 'Test_repeat_many()',
-      \ 'Test_repeat_three()',
       \ 'Test_server_crash()',
-      \ 'Test_stop_all_in_callback()',
       \ 'Test_terminal_ansicolors_default()',
       \ 'Test_terminal_ansicolors_func()',
       \ 'Test_terminal_ansicolors_global()',
@@ -359,9 +354,15 @@
       \ 'Test_terminal_wall()',
       \ 'Test_terminal_wipe_buffer()',
       \ 'Test_terminal_wqall()',
+      \ 'Test_timer_oneshot()',
+      \ 'Test_timer_paused()',
+      \ 'Test_timer_repeat_many()',
+      \ 'Test_timer_repeat_three()',
+      \ 'Test_timer_stop_all_in_callback()',
+      \ 'Test_timer_stop_in_callback()',
       \ 'Test_two_channels()',
       \ 'Test_unlet_handle()',
-      \ 'Test_with_partial_callback()',
+      \ 'Test_timer_with_partial_callback()',
       \ 'Test_zero_reply()',
       \ 'Test_zz1_terminal_in_gui()',
       \ ]