Patch: Fix for PR 2369

[Tom Tromey]

>>>>> "Bryce" == Bryce McKinlay <bryce@waitaki.otago.ac.nz> writes:

Bryce> I'm not sure now whether its a good idea to try and validate
Bryce> that the specified --main exists when linking .o files, since
Bryce> it would depend on the given class being findable on the
Bryce> current sourcepath/classpath, and it may not neccessarily be
Bryce> there in all cases.

It would be nice to print a message from the compiler, since you would
see it sooner -- linking is slow.  But is this a requirement?  Another
approach here would be to find a way to get the linker to generate a
nicer error message for us.  This only works on free systems, but
maybe that's enough.  Comments?

Tom