Now remove the addition of "start/*" packages in 'packpath' as
explicit items in 'runtimepath'. This avoids 'runtimepath' from becoming
very long when using a lot of plugins as packages.

To get the effective search path as a list, use |nvim_list_runtime_paths()|

Note that these are not NUL-terminated; the API supports this.

Problem:    Cannot handle binary data.
Solution:   Add the Blob type. (Yasuhiro Matsumoto, closes vim/vim#3638)
https://github.com/vim/vim/commit/6e5ea8d2a995b32bbc5972edc4f827b959f2702f

Nvim-specific Blob conversions are implemented in future commits.

Refactor write_blob() to use a FileDescriptor, as f_writefile() was
refactored to use one (does not apply to read_blob()).

Use var_check_lock() in f_add() for Blobs from v8.1.0897.

Add a modeline to test_blob.vim and fix some doc typos.

Include if_perl.txt's VIM::Blob() documentation. Interestingly, this
function already worked before this port, as it just returns a Blob
string literal, not an actual Blob object.

N/A patches for version.c:

vim-patch:8.1.0741: viminfo with Blob is not tested

Problem:    Viminfo with Blob is not tested.
Solution:   Extend the viminfo test.  Fix reading a blob.  Fixed storing a
            special variable value.
https://github.com/vim/vim/commit/8c8b8bb56c724cc1bfc3d8520eec33f2d399697c

vim-patch:8.1.1022: may use NULL pointer when out of memory

Problem:    May use NULL pointer when out of memory. (Coverity)
Solution:   Check for blob_alloc() returning NULL.
https://github.com/vim/vim/commit/e142a9467a7f6845a426d8db6efedf246d3c13ac

ref #11456

fix #11456

Extmarks mostly use api-indexing, except for nvim_buf_get_extmarks(),
which uses api-indexing with inclusive ranges.

ref #11456

ref #15440

Converter functions use a heap-allocated stack to handle complex
nested objects. However, these are often called with simple,
primitive values like integers or bools wrapped in an Object.
Avoid the memory allocation in this case using kvec_withinit_t