vim-patch:8.1.0735: cannot handle binary data

Problem:    Cannot handle binary data.
Solution:   Add the Blob type. (Yasuhiro Matsumoto, closes vim/vim#3638)
6e5ea8d2a9

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.
8c8b8bb56c

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.
e142a9467a

src/nvim/eval.h

@@ -63,6 +63,7 @@ typedef struct lval_S {
     dict_T *ll_dict;    ///< The Dictionary or NULL.
     dictitem_T *ll_di;  ///< The dictitem or NULL.
     char_u *ll_newkey;  ///< New key for Dict in allocated memory or NULL.
+    blob_T *ll_blob;    ///< The Blob or NULL.
 } lval_T;
 
 /// enum used by var_flavour()
@@ -154,6 +155,7 @@ typedef enum {
     VV_TYPE_DICT,
     VV_TYPE_FLOAT,
     VV_TYPE_BOOL,
+    VV_TYPE_BLOB,
     VV_EVENT,
     VV_ECHOSPACE,
     VV_ARGV,