Move name_to_pass_map into class pass_manager

Move name_to_pass_map into class pass_manager

gcc/ChangeLog:
	* pass_manager.h (pass_manager::register_pass_name): New method.
	(pass_manager::get_pass_by_name): New method.
	(pass_manager::create_pass_tab): New method.
	(pass_manager::m_name_to_pass_map): New field.
	* passes.c (name_to_pass_map): Delete global in favor of field
	"m_name_to_pass_map" of pass_manager.
	(register_pass_name): Rename from a function to...
	(pass_manager::register_pass_name): ...this method, updating
	for renaming of global "name_to_pass_map" to field
	"m_name_to_pass_map".
	(create_pass_tab): Rename from a function to...
	(pass_manager::create_pass_tab): ...this method, updating
	for renaming of global "name_to_pass_map" to field.
	(get_pass_by_name): Rename from a function to...
	(pass_manager::get_pass_by_name): ...this method.
	(enable_disable_pass): Convert use of get_pass_by_name to
	a method call, locating the pass_manager singleton.

From-SVN: r235977