Make function assembly more independent.

Make function assembly more independent.

This is achieved by having clone_function_name assign unique clone
numbers for each function independently.

gcc:

	* cgraphclones.c: Replaced clone_fn_id_num with clone_fn_ids;
	hash map.
	(clone_function_name_numbered): Use clone_fn_ids.

gcc/testsuite:

	* gcc.dg/independent-cloneids-1.c: New test.

From-SVN: r266691