Variable: Buffer-menu-buffer+size-width

Combined width of buffer name and size columns in Buffer Menu.
If nil, use `Buffer-menu-name-width' and `Buffer-menu-size-width'.

If non-nil, the value of `Buffer-menu-name-width' is overridden;
the name column is assigned width `Buffer-menu-buffer+size-width'
minus `Buffer-menu-size-width'. This use is deprecated.