Fortran: Fix problems with class array function selectors [PR112834]

Fortran: Fix problems with class array function selectors [PR112834]

2023-12-16  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/112834
	* match.cc (build_associate_name): Fix whitespace issues.
	(select_type_set_tmp): If the selector is of unknown type, go
	the SELECT TYPE selector to see if this is a function and, if
	the result is available, use its typespec.
	* parse.cc (parse_associate): Again, use the function result if
	the type of the selector result is unknown.
	* trans-stmt.cc (trans_associate_var): The expression has to be
	of type class, for class_target to be true. Convert and fix
	class functions. Pass the fixed expression.

	PR fortran/111853
	* resolve.cc (gfc_expression_rank): Avoid null dereference.

gcc/testsuite/
	PR fortran/112834
	* gfortran.dg/associate_63.f90 : New test.

	PR fortran/111853
	* gfortran.dg/pr111853.f90 : New test.