(main): Ignore the argument to -o.
(main): Place o_file after an initial .o (like crt0.o).
If we have LD_INIT_SWITCH, use init and fini functions for
executables, too.  Specify the unique function names.
(write_c_file_stat): Fix the case of destructors but no constructors.
Don't include the generic-named functions for executables.
(write_c_file): If we have LD_INIT_SWITCH, always use write_c_file_stat.
(main): Also add _GLOBAL__D? to export list.

From-SVN: r9956