enable static libgcj on darwin

[Andrew Pinski]

> This patch makes static libgcj builds work on Darwin.
> 
> Since darwin doesn't have a crtbegin.o/crtend.o (gcc only supports
> this for COFF and ELF), the jcr section doesn't really work.  Until
> there is support for Mach-O in crtbegin/end, we need to fall back to
> alternative methods of getting classes registered.
> 
> Ok to commit?


This is wrong.  Darwin does have support for JCR sections.
See libjava/darwin.cc which is used to support for JCR sections.
Now if it is not being linked in, that is a different story and can
be fixed a different way by using a .o instead of putting it into
the .a.

Thanks,
Andrew Pinski