Fortran: Remove adding and removing of caf_get. [PR107635]

Fortran: Remove adding and removing of caf_get. [PR107635]

Preparatory work for PR107635.

During resolve prevent adding caf_get calls for expressions on the
left-hand-side of an assignment and removing them later on again.

Furthermore has the caf_token in a component become a pointer to
the component and not the backend_decl of the caf-component.
In some cases the caf_token was added as last component in a derived
type and not as the next one following the component that it was
needed to be associated to.

gcc/fortran/ChangeLog:

	PR fortran/107635

	* gfortran.h (gfc_comp_caf_token): Convenient macro for
	accessing caf_token's tree.
	* resolve.cc (gfc_resolve_ref): Backup caf_lhs when resolving
	expr in array_ref.
	(remove_caf_get_intrinsic): Removed.
	(resolve_variable): Set flag caf_lhs when resolving lhs of
	assignment to prevent insertion of caf_get.
	(resolve_lock_unlock_event): Same, but the lhs is the parameter.
	(resolve_ordinary_assign): Move conversion to caf_send to
	resolve_codes.
	(resolve_codes): Adress caf_get and caf_send here.
	(resolve_fl_derived0): Set component's caf_token when token is
	necessary.
	* trans-array.cc (gfc_conv_array_parameter): Get a coarray for
	expression that have a corank.
	(structure_alloc_comps): Use macro to get caf_token's tree.
	(gfc_alloc_allocatable_for_assignment): Same.
	* trans-expr.cc (gfc_get_ultimate_alloc_ptr_comps_caf_token):
	Same.
	(gfc_trans_structure_assign): Same.
	* trans-intrinsic.cc (conv_expr_ref_to_caf_ref): Same.
	(has_ref_after_cafref): New function to figure that after a
	reference of a coarray another reference is present.
	(conv_caf_send): Get rhs from correct place, when caf_get is
	not removed.
	* trans-types.cc (gfc_get_derived_type): Get caf_token from
	component and no longer guessing.