bug#17848: add suffix search to -l even when directory part in argument

[Glenn Morris]

Package: emacs
Version: 24.4
Severity: wishlist

`emacs -L . -l foo' searches for foo.elc or foo.el in PWD.

`emacs -l ./foo' tries to open a file literally name "foo", with no suffix.
I wish it would still do the suffix search even when the file name
contains a directory part.

Motivation: when you don't know whether foo.elc exists or not
(eg you don't know whether foo.el contains no-byte-compile or not),
and you don't want to add the directory containing foo to load-path.