Problem:    Options test script does not work.
Solution:   Use optiondefs.h for input.
https://github.com/vim/vim/commit/d9b0d83b13d2691e4544709abd87eac004715175

Problem:    No statistics displayed after running tests.
Solution:   Summarize the test results. (Christian Brabandt, closes vim/vim#4391)
            Also make it possible to report a skipped file.
https://github.com/vim/vim/commit/9c0cec65f891492314caadeef87a50251a21e630

Removes our custom no-inits from `$(RUN_VIMTEST)`, since we have
`$(NO_INITS)` now also.

Vim turns on 'compatible' as a side effect of using the -u command line
option. As a result, viminfo is not used. But that is not the case with
neovim. neovim requires the -i command line option to avoid breaking
user's viminfo.

Test52 does nothing on UNIX. And vim on Windows performs mbyte-conversion
between Unicode and code page using Windows API(See :h mbyte-conversion).
Test52 seems to be testing its functionality. In neovim, the conversion
function by Windows API has been removed. Therefore, there is no point
in doing this test.

In Windows, since conversion of the line feed code is necessary, porting
fixff target from Make_mingw.mak of vim.

Previously it would be displayed across multiple lines (with the escaped
newlines), while this makes it display in a single line.

Run failing tests, added in vim-patch:8.1.0493.

Problem:    Test 37 is old style.
Solution:   Turn it into a new style test. (Yegappan Lakshmanan, closes vim/vim#4398)
https://github.com/vim/vim/commit/999dc14644b8a9530ce0da22e90ca402c95c9c5a

Problem:    Test17 is old style.
Solution:   Turn into new style test. (Yegappan Lakshmanan, closes vim/vim#4347)
https://github.com/vim/vim/commit/f0ab01f6d868164ed0bb247b6f7b152e6929ef18