Problem:    Windows cannot be identified.
Solution:   Add a unique window number to each window and functions to use it.

https://github.com/vim/vim/commit/86edef664efccbfe685906c854b9cdd04e56f2d5

Problem:    Visual-block shift breaks multi-byte characters.
Solution:   Compute column differently. (Yasuhiro Matsumoto) Add a test.

https://github.com/vim/vim/commit/20b4f463f4ab50fa9bcc9838aa94101fa5698125

These tests should be here, not in the Makefile.

Problem:    Sticky type checking is more annoying than useful.
Solution:   Remove the error for changing a variable type.

https://github.com/vim/vim/commit/f6f32c38bf3319144a84a01a154c8c91939e7acf

Note: There are a bunch of other changes to eval.txt that I believe are
N/A and not related to this patch.

vim-patch:7.4.{1090,1094}

Problem:    Segfault when unletting "count".
Solution:   Check for readonly and locked first. (Dominique Pelle)
            Add a test.

https://github.com/vim/vim/commit/af8af8bfac5792fa64efbc524032d568cc7754f7

vim-patch:7.4.{1150,1151}

tests: Migrate legacy test 55