* lisp/vc/log-edit.el (log-edit--insert-filled-defuns): Don't
open a new line for long defuns at column 0.
* test/lisp/vc/log-edit-tests.el
(log-edit-fill-entry-space-substitution): Adjust expected
results to match change.
(log-edit-fill-entry-initial-wrapping): New test.