libgcj on cygwin

[Jeff Sturm]

I took a look at the latest Cygwin during the weekend.  Cygwin now installs
gcj-2.95.2 now along with the rest of the GCC compiler suite, but no libgcj... I
hadn't realized they were doing that.  It explains why we're getting
semifrequent questions about Cygwin on the list.

There are no binary kits available other than the one at
http://www.cs.bris.ac.uk/~jb7216/libgcj/ which doesn't seem to be updated often.

I took a stab at building current gcj/libgcj on Cygwin.  It compiles OK with a
few changes, though I don't recommend attempting to build natively (watching
libtool run on an emulated POSIX system is quite painful).  The biggest change
is that alloca(), upon which libgcj currently depends, is broken on Cygwin.

The interpreter seems to work, as does GC.  There are no threads for now,
although since Cygwin is now reentrant a win32-thread version ought to be
possible.

If there is still any interest I'll post my patch and binaries somewhere.  Note
that it'll require a recent compiler snapshot.  (I might even try backporting to
2.95, though that is very out of date.)

--
Jeff Sturm
jeff.sturm@commerceone.com