Fix the parsing of the newline in the (lang ...) line (#1390)
Fix the parsing of the newline in the (lang ...) line (#1390)

Currently it was ignored, causing error messages to be incorrectly
located.

Signed-off-by: Jeremie Dimino <aa5d8c8bb73d4465608582ffc8dcd3cb76639f53@dimino.org>
janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder,dra27/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder