Enhancement of call graph API

Enhancement of call graph API

	* cgraph.h (expand_thunk): New argument added.
	(address_taken_from_non_vtable_p): New global function.
	* ipa-visibility.c (address_taken_from_non_vtable_p): Likewise.
	* cgraphclones.c (duplicate_thunk_for_node): Argument added to call.
	* cgraphunit.c (analyze_function): Likewise.
	(assemble_thunks_and_aliases): Argument added to call.
	(expand_thunk): New argument forces to produce GIMPLE thunk.

From-SVN: r211218