[Bug bootstrap/77995] gcc 6.2.0 failed on somparison stage 2 & 3

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77995

--- Comment #4 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
If BUILD_CONFIG is empty, then a possible fix is at:
  https://gcc.gnu.org/ml/gcc-cvs/2016-10/msg00278.html