When avoiding double deallocation, look at namespace, expression and component.

When avoiding double deallocation, look at namespace, expression and component.

Our finalization handling is a mess.  Really, we should get to try and get
this fixed for gcc 11.

In the meantime, here is a patch which fixes a regression I introduced
when fixing a regression with a memory leak.  The important thing
here is to realize that we do not need to finalize (and deallocate)
multiple times for the same expression and the same component
in the same namespace.  It might cause code size regressions, but
better big code than wrong code...

gcc/fortran/ChangeLog:

	PR fortran/94109
	* class.c (finalize_component): Return early if finalization has
	already happened for expression and component within namespace.
	* gfortran.h (gfc_was_finalized): New type.
	(gfc_namespace): Add member was_finalzed.
	(gfc_expr): Remove finalized.
	* symbol.c (gfc_free_namespace): Free was_finalized.

gcc/testsuite/ChangeLog:

	PR fortran/94109
	* gfortran.dg/finalize_34.f90: Adjust free counts.
	* gfortran.dg/finalize_36.f90: New test.