[snip Todd's test case]

I also saw this screwy behaviour on a Shark at the weekend, this time
compiling one of the big C++ files in Mozilla. As-per Todd's report, cc1
displayed some text which wasn't in the source file at the specified
line. Maybe it's related to the random wedges I've been seeing since I
upgraded my Sharks to -current, particularly after Mozilla sessions...
(I'm also seeing mvme68k-current occasionally wedge after heavy use).

Sorry I can't narrow this down any further.

Cheers, Steve