The Fortran 2018 standard defines the concept of simple contiguity
in subclause 9.5.4 as a characteristic of arrays. So that scalars
may also be used in contexts where simply contiguous arrays are
allowed, f18 treats them as single-element arrays that are trivially
contiguous. This patch documents this semantic extension and
also adds comments to the predicate that implements the concept.
Differential Revision: https://reviews.llvm.org/D111679
6ee2aa126c