[flang] Allow for equivalent types in non-TBP defined I/O (#158755)
Non-extensible derived type -- those with SEQUENCE or BIND(C) -- are
allowed as monomorphic "dtv" dummy arguments to defined I/O subroutines.
Fortran's type rules admit structural equivalence for these types, and
it's possible that I/O might be attempted in a scope using a
non-extensible type that's equivalent to a non-type-bound generic
interface's specific procedure's "dtv" dummy argument's type, but not
defined in the same place.
Fixes https://github.com/llvm/llvm-project/issues/158673.
This is an IBM Fortran test case that doesn't need to be duplicated in
LLVM.
llvm-project
deb2861b - [flang] Allow for equivalent types in non-TBP defined I/O (#158755)
