Problem: Cannot use positional arguments for printf()
Solution: Support positional arguments in string formatting

closes: vim/vim#12140

https://github.com/vim/vim/commit/0c6181fec4c362eb9682d5af583341eb20cb1af5

Co-authored-by: Christ van Willegen <cvwillegen@gmail.com>

Adjust relevant Lua tests. Refactor testing logic for tv_get_string_*
functions into test_string_fn().

Note that vim_snprintf(), which is used for stringifying floats, always
calls xfree(tofree), even if tofree is NULL, so we need to expect that
in the alloc log.

If last_msg_hist is NULL, check_emsg will cause the running test process
to SIGSEGV from trying to access the msg member.

Problem:    Slightly inconsistent error messages.
Solution:   Make it "Using a Float". (closes vim/vim#10959)

https://github.com/vim/vim/commit/dde77a7c4d72622284dc5fb72557bde42c314fa6

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

Problem:    Inconsistent capitalization in error messages.
Solution:   Make capitalization consistent. (Doug Kearns)

https://github.com/vim/vim/commit/cf030578b26460643dca4a40e7f2e3bc19c749aa

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

Problem:    Vim9: builtin function arguments not checked at compile time.
Solution:   Add more type checks. (Yegappan Lakshmanan, closes vim/vim#8539)

https://github.com/vim/vim/commit/5b73992d8f82be7ac4b6f46c17f53ffb9640e5fa

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

Problem:    Vim9: script cannot use line continuation like in a :def function.
Solution:   Pass the getline function pointer to the eval() functions.  Use it
            for addition and multiplication operators.

https://github.com/vim/vim/commit/5409f5d8c95007216ae1190565a7a8ee9ebd7100

Omit source_nextline() and eval_next_non_blank(): Vim9 script only.

N/A patches for version.c:

vim-patch:8.2.1048: build failure without the eval feature

Problem:    Build failure without the eval feature.
Solution:   Add dummy typedef.

https://github.com/vim/vim/commit/9d40c63c7dc8c3eb3886c58dcd334bc7f37eceba

vim-patch:8.2.1052: build failure with older compilers

Problem:    Build failure with older compilers.
Solution:   Move declaration to start of block.

https://github.com/vim/vim/commit/7acde51832f383f9a6d2e740cd0420b433ea841a

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

vim-patch:8.2.0695: Vim9: cannot define a function inside a function

Problem:    Vim9: cannot define a function inside a function.
Solution:   Initial support for :def inside :def.

https://github.com/vim/vim/commit/04b12697838b232b8b17c553ccc74cf1f1bdb81c

vim-patch:8.2.0725: Vim9: cannot call a function declared later in Vim9 script

Problem:    Vim9: cannot call a function declared later in Vim9 script.
Solution:   Make two passes through the script file.

https://github.com/vim/vim/commit/09689a02840be40fa7bb10b1921fb5bc5b2908f1

vim-patch:8.2.0734: Vim9: leaking memory when using :finish

Problem:    Vim9: leaking memory when using :finish.
Solution:   Do not check for next line in third pass.

https://github.com/vim/vim/commit/04816717dfea6e2469ff4c9d40f68b59aaf03724

vim-patch:8.2.0753: Vim9: expressions are evaluated in the discovery phase

Problem:    Vim9: expressions are evaluated in the discovery phase.
Solution:   Bail out if an expression is not a constant.  Require a type for
            declared constants.

https://github.com/vim/vim/commit/32e351179eacfc84f64cd5029e221582d400bb38

vim-patch:8.2.0818: Vim9: using a discovery phase doesn't work well

Problem:    Vim9: using a discovery phase doesn't work well.
Solution:   Remove the discovery phase, instead compile a function only when
            it is used.  Add :defcompile to compile def functions earlier.

https://github.com/vim/vim/commit/822ba24743af9ee1b5e7f656a7a61a38f3638bca

vim-patch:8.2.0819: compiler warning for unused variable

Problem:    Compiler warning for unused variable.
Solution:   Remove the variable.

https://github.com/vim/vim/commit/f40e51a880a95f94dbbbecc9476559506c2cc345

vim-patch:8.2.0822: Vim9: code left over from discovery phase

Problem:    Vim9: code left over from discovery phase.
Solution:   Remove the dead code.

https://github.com/vim/vim/commit/2eec37926db6d31beb36f162ac00357a30c093c8

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

Closes https://github.com/neovim/neovim/issues/459