vim-patch:8.2.0928: many type casts are used for vim_strnsave()

Problem:    Many type casts are used for vim_strnsave().
Solution:   Make the length argument size_t instead of int. (Ken Takata,
            closes vim/vim#5633)  Remove some type casts.
df44a27b53

N/A patches for version.c:

vim-patch:8.2.0315: build failure on HP-UX system

Problem:    Build failure on HP-UX system.
Solution:   Use LONG_LONG_MIN instead of LLONG_MIN.  Add type casts for switch
            statement. (John Marriott)
c593bec412

vim-patch:8.2.1052: build failure with older compilers

Problem:    Build failure with older compilers.
Solution:   Move declaration to start of block.
7acde51832

vim-patch:8.2.2229: build failure without the +eval feature

Problem:    build failure without the +eval feature.
Solution:   Add #ifdef.
39cb2dab18

vim-patch:8.2.2232: compiler error for falling through into next case

Problem:    Compiler error for falling through into next case.
Solution:   Move FALLTHROUGH below the #endif
9618a25b9c

src/nvim/edit.c

@@ -3423,7 +3423,7 @@ static void ins_compl_addleader(int c)
 
   xfree(compl_leader);
   compl_leader = vim_strnsave(get_cursor_line_ptr() + compl_col,
-      (int)(curwin->w_cursor.col - compl_col));
+                              curwin->w_cursor.col - compl_col);
   ins_compl_new_leader();
 }