This patch is straightforward but the isolation of the problem was rather
less so. Many thanks to Juergen for testcase reduction.

Regtested on FC33/x86_64 - OK for master?

Paul

Fortran: Fix problem with runtime pointer chack [PR99602].

2021-03-26  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran/ChangeLog

PR fortran/99602
* trans-expr.c (gfc_conv_procedure_call): Use the _data attrs
for class expressions and detect proc pointer evaluations by
the non-null actual argument list.

gcc/testsuite/ChangeLog

PR fortran/99602
* gfortran.dg/pr99602.f90: New test.
* gfortran.dg/pr99602a.f90: New test.
* gfortran.dg/pr99602b.f90: New test.