Meta issue: Reduce number of testcase failures in vim:

[MikeFultonDev]

Here is the 'jenkins' list (which is 2 more than the list on the zoscan2b IBM z/OS system):

Test_buflist_alloc_failure():
Test_source_files():
Test_digraph_get_function_encode():
Test_show_digraph_cp1251():
Test_edit_overlong_file_name():
Test_exit_code():
Test_printf_float():
Test_screen_functions():
Test_strftime():
Test_increment_dbcs_1():
Test_map_timeout_with_timer_interrupt():
Test_menu_info():
Test_normal_changecase_turkish():
Test_autocmd_changelist():
Test_cquit():
Test_grep():
Test_locationlist_cross_tab_jump():
Test_smoothscroll_marker_over_double_width():
Test_search_timeout():
Test_searchpair_timeout():
Test_searchpair_timeout_with_skip():
Test_shell_options():
Test_aff_file_format_error():
Test_undofile():
Test_patchmode():
Test_readwrite_file_with_bom():
Test_saveas():
Test_wq_quitpre_autocommand():
Test_write_autocmd_add_remove_lines():
Test_write_backup_symlink():
Test_write_binary_file():
Test_write_pipe_to_cmd():
Test_write_quit_split():
Test_write_readonly():
Test_writefile_fails_conversion():
Test_xxd():
Test_xxd_bit_dump():
Test_xxd_color():
Test_xxd_patch():
Test_xxd_patch_with_bitdump():
Test_read_fifo_utf8():
Test_compiler():

Need to reduce the number of failures

[MikeFultonDev]

See #27 for attachment