To strip down a new version of gdb for import, extract
the files like this:

    tar -xvzf gdb-4.18.tar.gz -X FREEBSD-Xlist
    tar -xvzf gdb-4.18.tar.gz gdb-4.18/gdb/config/i386
    tar -xvzf gdb-4.18.tar.gz gdb-4.18/gdb/config/alpha
    tar -xvzf gdb-4.18.tar.gz gdb-4.18/gdb/config/mips


