[Bug fortran/83606] [6/7/8 Regression] co-indexed array RHS yields incorrect result in assignment to vector-indexed LHS

[vehre at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83606

--- Comment #7 from vehre at gcc dot gnu.org ---
Backporting to gcc-6 and -7 is possible. The patch applies cleanly and all
regression tests pass.