Comment # 3 on bug 1099119 from Richard Biener

This is the same issue as bnc#1097283.  It looks like the resp. revision is now
backported to the GCC 6 branch but not yet GCC 7 ...

GCC 6 changelog:

2018-06-15  Martin Liska  <mliska@suse.cz>

        PR bootstrap/86162

        Backport from mainline
        2018-01-10  Kelvin Nilsen  <kelvin@gcc.gnu.org>

        * lex.c (search_line_fast): Remove illegal coercion of an
        unaligned pointer value to vector pointer type and replace with
        use of __builtin_vec_vsx_ld () built-in function, which operates
        on unaligned pointer values.