https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115138
--- Comment #17 from Iain Sandoe <iains at gcc dot gnu.org> --- however, the opover.o mismatch is a symptom - rather than the cause. If all the objects for the D FE are built by D, then that would tend to point to miscompilation of something in common code (that is built with C++ and therefore can be affected by O3).
