Only finalize dot files that have been initialized

Only finalize dot files that have been initialized

2016-04-17  Tom de Vries  <tom@codesourcery.com>

	PR other/70185
	* tree-pass.h (class opt_pass): Remove graph_dump_initialized member.
	* dumpfile.h (struct dump_file_info): Add graph_dump_initialized field.
	* dumpfile.c (dump_files): Initialize graph_dump_initialized field.
	* passes.c (finish_optimization_passes): Only call
	finish_graph_dump_file if dfi->graph_dump_initialized.
	(execute_function_dump, pass_init_dump_file): Use
	dfi->graph_dump_initialized instead of pass->graph_dump_initialized.

From-SVN: r235074