fortran: Fix ICE in ALLOCATE of sub-objects with recursive types

The deep-copy wrapper generation for recursive allocatable array
components (PR121628) calls cgraph_node::add_new_function to register
the wrapper.  During PARSING state, add_new_function calls
finalize_function which triggers ggc_collect().  This garbage
collection frees locally-computed tree nodes (COMPONENT_REFs etc.)
in caller stack frames of structure_alloc_comps that are not yet
attached to any GC-rooted structure, causing a segfault when those
nodes are subsequently accessed.

Use finalize_function with no_collect=true to skip the collection.
The GC will run at a safe point later.

	PR fortran/124235

gcc/fortran/ChangeLog:

	* trans-array.cc (generate_element_copy_wrapper): Use
	cgraph_node::finalize_function with no_collect=true instead
	of cgraph_node::add_new_function to avoid garbage collection
	while caller frames hold unrooted tree nodes.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr124235.f90: New test.

Signed-off-by: Christopher Albert <albert@tugraz.at>