The new oldtest directory is in test/old/testdir. The reason for this is
that many tests have hardcoded the parent directory name to be
'testdir'.

Problem:    Test fails without the 'autochdir' option.
Solution:   Check that the option is available. (Dominique Pellé, closes vim/vim#9272)

https://github.com/vim/vim/commit/8dea145e39a2569153cb63487d3403a46a882189

Co-authored-by: Dominique Pelle <dominique.pelle@gmail.com>

Problem:    assert_fails() checks the last error message.
Solution:   Check the first error, it is more relevant.  Fix all the tests
            that rely on the old behavior.

https://github.com/vim/vim/commit/9b7bf9e98f06ece595fed7a3ff53ecce89797a53

Skip test_listener.vim, test_textprop.vim, test_viminfo.vim.
Skip test_python2.vim: affected line fails and hasn't been ported.
Skip test_python3.vim: affected lines fail and haven't been ported.
Skip CHECK_LIST_MATERIALIZE.

Co-authored-by: Bram Moolenaar <Bram@vim.org>

Problem:    Some 'cpoptions' not tested.
Solution:   Add more tests. (Yegappan Lakshmanan, closes vim/vim#6253)

https://github.com/vim/vim/commit/df7df59d85e7e56a796912dc865488a75d3f0e53

vim-patch:8.1.1915: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
https://github.com/vim/vim/commit/1a3a89168d61c2fed91cbca812cf1c6983901b79

Move debugbreak() to the right place.

vim-patch:8.1.1921: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
https://github.com/vim/vim/commit/a4208966fb289a505ebdef62bbc37c214069bab4

vim-patch:8.1.1953: more functions can be used as a method

Problem:    More functions can be used as a method.
Solution:   Allow more functions to be used as a method.
https://github.com/vim/vim/commit/f9f24ce7a0e5988fedf2e2ff751818f9b07510a6

Omit test_termcodes.vim: cannot be used and superseded by later patches.
Cherry-pick test_bufline.vim change from patch 8.1.1993.

Problem:    Command line completion not fully tested.
Solution:   Add more test cases.  Make help sorting stable. (Dominique Pelle,
            closes vim/vim#5402)
https://github.com/vim/vim/commit/297610ba4b110c918ffe60c45eb4a1d6ea2daae5

Problem:    After ":cd" fails ":cd -" is incorrect.
Solution:   Set the previous directory only after successfully changing
            directory. (Richard Doty, closes vim/vim#9419, closes vim/vim#8983)
https://github.com/vim/vim/commit/3d0abad5bf4fe125e219f1b56c4e8200cb900e2a

Adjust the test's error message check due to missing patch

vim-patch:8.2.3973: tiny build fails

Problem:    Tiny build fails.
Solution:   Adjust #ifdefs
https://github.com/vim/vim/commit/0f7a5e758c5d8be2d8f1ab4a145d1636a36d18b2

vim-patch:8.2.3978: build error when using dynamycally loaded Python 3

Problem:    Build error when using dynamycally loaded Python 3.
Solution:   Adjust #ifdef.
https://github.com/vim/vim/commit/6b1a99dfe33cf5a1d7f82febd81face85ac1b8a6

vim-patch:8.2.4013: build failure without the spell feature

Problem:    Build failure without the spell feature.
Solution:   Adjust #ifdefs.
https://github.com/vim/vim/commit/e60b3c47d701e73ecbadb1b9a12bf82010cadae8

vim-patch:8.2.4032: ATTRIBUTE_NORETURN is not needed

Problem:    ATTRIBUTE_NORETURN is not needed.
Solution:   Use NORETURN(). (Ozaki Kiichi, closes vim/vim#9487)
https://github.com/vim/vim/commit/e12406526a24768e6121450112eb2f9f92445ac5

vim-patch:8.2.4048: gcc complains about use of "%p" in printf

Problem:    gcc complains about use of "%p" in printf.
Solution:   Add (void *) typecast. (Dominique Pellé, closes vim/vim#9494)
https://github.com/vim/vim/commit/c14f667626ba677a767d474324306e39096dc43e

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
https://github.com/vim/vim/commit/4c313b13fb7bfa694ec6d2a13175e8650c007b2a

The rest of this patch was ported in
https://github.com/neovim/neovim/commit/3137c7d63574a86ddc44f11c839e8e58c2994bf9

N/A patches for version.c:

vim-patch:8.1.2012: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make terminal functions usable as a method.  Fix term_getattr().
https://github.com/vim/vim/commit/7ee80f766130f22598c928415c92ec612a8f18cf

vim-patch:8.2.3576: some functions are not documented for use with a method

Problem:    Some functions are not documented for use with a method.
Solution:   Add examples.  Fix that sign_unplacelist() only takes one
            argument. (Sean Dewar, closes vim/vim#9081)
https://github.com/vim/vim/commit/a63780b9770699bf8fda93affeab2c728bc76912

Addressed in the port of v8.1.1995.

Problem:    getcwd() is unclear about how 'autochdir' is used.
Solution:   Update the help for getcwd().  Without any arguments always return
            the actual current directory. (closes vim/vim#9142)
https://github.com/vim/vim/commit/851c7a699ae00bdc14a4db874cf722b7b7393b53

Problem:    Problem with :cd when editing file in non-existent directory. (Yee
            Cheng Chin)
Solution:   Prepend the current directory to get the full path. (closes vim/vim#8903)
https://github.com/vim/vim/commit/c6376c798433bcb9ee38a8664299d11454546950