Semantic parser uses c-forward-conditional

[Chong Yidong]

Hi Alan,

Semantic's C parser calls c-forward-conditional while it's parsing C
files.  This happens frequently, often at idle time, if you visit a
large C file.

The trouble is that c-forward-conditional sets the mark.  The call to it
is wrapped in a save-excursion, so it doesn't clobber the user's mark,
but it does lead to a stream of ugly "Mark set" messages.

Would it be possible to change c-forward-conditional so that it pushes
the mark only if called interactively?