[flang] Check for attributes specific to dummy arguments

We were not checking that attributes that are supposed to be specific to
dummy arguments were not being used for local entities.  I added the checks
along with tests for them.

After implementing these new checks, I found that one of the tests in
separate-mp02.f90 was erroneous, and I fixed it.

Differential Revision: https://reviews.llvm.org/D101126