Simplify 'without-restriction'

Simplify 'without-restriction'

This simplification is symmetrical to 01fb898420.

* src/editfns.c: (Finternal__labeled_widen): Add a call to
'Fwiden', and rename from 'internal--unlabel-restriction'.
(unwind_labeled_narrow_to_region): Use the renamed function, and
remove the call to 'Fwiden'.
(syms_of_editfns): Rename the symbol.

* lisp/subr.el (internal--without-restriction): Use the renamed
function.

(cherry picked from commit 9e9e11648d3d5514de85edfb69f0949a062f4716)