* gimple-ssa.h (gimple_df): Add free_ssanames_queue field.
	* passes.c: Include tree-ssanames.h.
	(execute_function_todo): Flush the pending free SSA_NAMEs after
	eliminating unreachable basic blocks.
	* tree-ssanames.c (FREE_SSANAMES_QUEUE): new.
	(init_ssanames): Initialize FREE_SSANAMES_QUEUE.
	(fini_ssanames): Finalize FREE_SSANAMES_QUEUE.
	(flush_ssanames_freelist): New function.
	(release_ssaname_fn): Put released names on the queue.
	(pass_release_ssa_names::execute): Call flush_ssanames_freelist.
	* tree-ssanames.h (flush_ssanames_freelist): Declare.

From-SVN: r228302