In the test case, there was a warning about INTENT where an EXTERNAL
masked an interface in an outer scope, when the location of the
symbol was not set, leading to an ICE.
Two problems, two-part solution: It makes no sense to warn about
INTENT for artificially generated formal argument lists, and the
location should be set.
gcc/fortran/ChangeLog:
PR fortran/96073
* frontend-passes.c (check_externals_procedure): Add locus
information for new_sym.
* interface.c (gfc_check_dummy_characteristics): Do not warn
about INTENT for artificially generated variables.
gcc/testsuite/ChangeLog:
PR fortran/96073
* gfortran.dg/interface_48.f90: New test.