Remove crud from RHEL < 8
    
    This patch removes a bunch of now dead code on RHEL
    prior to 8.  This permits us to also remove some
    baggage we've been carrying for many years: copies
    of libipt and libstdc++ pretty-printers.
    
    I've also attempted to deal with any warnings output
    by rpmdeplint.  There's still two remaining warnings
    with which to deal:
    
    gdb.spec:480: W: configure-without-libdir-spec
    gdb.spec:543: W: configure-without-libdir-spec
     0 packages and 1 specfiles checked; 0 errors, 2 warnings, 0 badness; has taken 0.2 s
    
    I have also NOT addressed any issues arising from '--with testsuite'
    or SCL builds.  I'll address those in follow-up patches.