NSBundle problems:

   It requires a small but important change in the objc runtime (see 
   gcc-dynamic.patch for info. It may be possible to work around this, but it
   is hard.  I already submitted this to gcc-bug, but don't know the
   status.

   It requires that the global variable NSArgv be defined and set to the
   value of argv in main() in order to find the executable location.

   Linking with different linkers and on different systems is different
   and may require some changes to the load flags, like -nostdlib,
   -shared, -Xlinker -r, etc... Some of this can be taken care of in 
   the configure script.