Problem:    No easy way to get the maximum or mininum number value.
Solution:   Add v:numbermax and v:numbermin.
https://github.com/vim/vim/commit/57d5a01cb45d6edb16c3835a49b42d6d8fc0163e

Problem:    Mixing up "long long" and __int64 may cause problems. (John
            Marriott)
Solution:   Pass varnumber_T to vim_snprintf().  Add v:numbersize.
https://github.com/vim/vim/commit/f9706e9df0e37d214fb08eda30ba29627e97a607

Problem:    Eval test fails because for loop on string works.
Solution:   Check looping over function reference fails.
https://github.com/vim/vim/commit/c61cb8bfe1ec2cc50e6edd195cae2a3cd93d6590

Problem:    Cursor on invalid line with range and :substitute.
Solution:   Do not move the cursor when skipping commands. (closes vim/vim#3434)
https://github.com/vim/vim/commit/df2c2988bbaecd28b0fbec8d64327b1bbb005e19

Cherry-pick Test_for_invalid() from patch v8.1.0736.

Problem:    Curly braces expression ending in " }" does not work.
Solution:   Skip over white space when checking for "}". (closes vim/vim#6634)
https://github.com/vim/vim/commit/ae95a3946b012d4e68bcb20b28f691f6d3b9caaf

Problem:    When skipping over code after an exception was thrown expression
            evaluation is aborted after a function call. (Ingo Karkat)
Solution:   Do not fail if not executing the expression. (closes vim/vim#4507)
https://github.com/vim/vim/commit/606407384144df73a6154aca1d77e071fe1b7651

Problem:    Crash when setting v:errmsg to empty list. (Jaon Franklin)
Solution:   Separate getting value and assigning result.
https://github.com/vim/vim/commit/4b9e91f0ba02192e4592a5c4a9bdcdd6e9efeb5e

Problem:    Error messages suppressed after ":silent! try". (Ben Reilly)
Solution:   Restore emsg_silent before executing :try. (closes vim/vim#2531)
https://github.com/vim/vim/commit/2be57331524e93da52a0663f4a334d21c05123bb

Problem:    Confusing overloaded operator "." for string concatenation.
Solution:   Add ".." for string concatenation.  Also "let a ..= b".
https://github.com/vim/vim/commit/0f248b006c2574abc00c9aa7886d8f33620eb822

Problem:    Continuation lines cannot contain comments.
Solution:   Support using "\ .
https://github.com/vim/vim/commit/67f8ab829911c7901c534ef2bf19cc34b622936f