[Bug c/80359] -O3 causes error: invalid reference prefix

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80359

--- Comment #2 from David Binderman <dcb314 at hotmail dot com> ---
This bug seems to have been introduced between revision 245052
and 245800 i.e. sometime during February 2017.