Make it possible to silence warnings issued when #'mapcar's result is discarded.
lisp/ChangeLog addition:
2009-10-19 Aidan Kehoe <kehoea@parhasard.net>
* bytecomp.el (byte-compile-default-warnings):
Add two new warning types, discarded-consing (basically use of
mapcar instead of mapc where its result is discarded) and
quoted-lambda (use of a lambda expression quoted as data in a
function context).
(byte-compile-warnings): Document the new warnings.
(byte-compile-fset, byte-compile-funarg): Implement the
quoted-lambda warning option.
(byte-compile-mapcar): Renamed to byte-compile-maybe-mapc.
(byte-compile-maybe-mapc, byte-compile-maplist):
Implement the discarded-consing warning option.
Add more functions that should be compiled using
byte-compile-funarg, notably mapvector, mapc-internal,
map-char-table.
* cl-macs.el (mapcar*):
If we know at compile time that there are no CL options being
used, use the mapcar subr, not the byte-coded function.
