sco5.h: Make ELF default file format and add -mcoff/-melf..

sco5.h: Make ELF default file format and add -mcoff/-melf..

        * i386/sco5.h: Make ELF default file format and add -mcoff/-melf..
        (MULTILIB_DEFAULTS): Define.
        (ASM_SPEC, CPP_SPEC): Handle -mcoff.
        (STARTFILE_SPEC, ENDFILE_SPEC, LINK_SPEC): Likewise.
        (LIBGCC_SPEC): Likewise.
        (MASK_COFF, TARGET_COFF, TARGET_ELF): Define.
        (SUBTARGET_SWITCHES): Add -mcoff and -melf.
        * i386/t-sco5 (CRTSTUFF_T_CFLAGS): Add -fPIC.
        (CRTSTUFF_T_CFLAGS_S): Tweak for COFF.
        (EXTRA_PARTS, TAROUTOPTS): Delete.
        (libgcc1-elf, libgcc2-elf, libgcc-elf targets): Delete.
        (MULTILIB_OPTIONS): Define.
        (MULTILIB_DIRNAMES, MULTILIB_EXCEPTIONS): Likewise.
        (MULTILIB_MATCHE, MULTILIB_EXTRA_OPTS): Likewise.
SCO Open Server patches.

From-SVN: r15627