This removes dead code that, according to the comments, existed to
placate lint. I don't think this has been relevant in a long time,
and certainly not since gdb switched to C++.
Tested by rebuilding.
ChangeLog
2018-07-30 Tom Tromey <tom@tromey.com>
* cli/cli-decode.c (lookup_cmd): Remove lint code.
* value.c (unpack_long): Remove lint code.
* valops.c (value_ind): Remove lint code.
* valarith.c (value_x_binop, value_x_unop, value_equal)
(value_pos): Remove lint code.