* configure.in: Disable collect2 for nextstep.  Instead use
        crtbegin/crtend.
        * configure: Rebuilt.
        * config/nextstep.h (STARTFILE_SPEC): Add crtbegin.
        (ENDFILE_SPEC): Define.
        (OBJECT_FORMAT_MACHO): Define.
        (EH_FRAME_SECTION_ASM_OP): Define.
        * crtstuff.c: Handle MACHO.

From-SVN: r22487