readelf.c (last_pointer_size, warned_about_missing_comp_units):
New variables associated with obtaining the pointer size for a comp_unit.
(get_pointer_size_of_comp_unit): Add an extra parameter - the name of the
section requesting the pointer size. Use this name in error messages. If
there are not enough comp_units available produce a warning message, but
return the last known pointer size so that section dumping can continue.
(get_debug_info): Reset the new variables.
(display_debug_lines): Add extra parameter to invocation of
get_pointer_size_of_comp_unit and remove error message when it returns 0.
(display_debug_loc): Likewise.