* net/tramp.el (tramp-root-regexp): Simplify.

* net/tramp.el (tramp-root-regexp): Simplify.
(tramp-completion-file-name-regexp-separate): Don't insist on
leading "[".  This prevents method or user or host completion.
(tramp-let-maybe): Autoload it.
(tramp-drop-volume-letter): Don't autoload.  When not on W32, it is
an alias for `identity'.
(tramp-handle-write-region): Protect `last-coding-system-used'
over the trailing statements.
(tramp-completion-file-name-handler-post-function): Removed.
(tramp-completion-file-name-handler): Let-bind
`directory-sep-char' instead of calling
`tramp-drop-volume-letter'.
(top): Move coding cookie at the end.