Polymorphic entity lowering status is good. The main remaining TODO is
to allow lowering of vector subscripted polymorphic entity, but this
does not deserve blocking all application using polymorphism.
Remove experimental option and enable lowering of polymorphic entity by
default.
A section of a parameter array may be non-contiguous,
so the current !IsVariable(expr) check is too optimistic
to claim contiguity.
This patch fixes issues with incorrect hlfir.designate op generated
during lowering: the lowering queries IsContiguous to decide whether
to use fir.box<fir.array> or plain fir.ref<fir.array> to represent
the designator result.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D156494