Type mismatch for passed external function

Type mismatch for passed external function

This obvious and simple patch fixes a 15/16 regression where the
typespec of a global function was in the RESULT clause and not
in the symbol itself.

gcc/fortran/ChangeLog:

	PR fortran/120355
	* interface.cc (compare_parameter): If the global function has a
	result clause, take typespec from there for the comparison against
	the dummy argument.

gcc/testsuite/ChangeLog:

	PR fortran/120355
	* gfortran.dg/interface_62.f90: New test.

(cherry picked from commit 0e77309047a7b479c89f03dcaf2994e050d0f33e)