(state::state): Initialize it.
	(state::clean_subrs): New method.
	(state::~state): Call it.
	(state::copy): Copy subroutine list.
	(state::add_subr): New method.
	(state::merge): Only register a change if the current subroutine
	hasn't yet been noted.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@62878 138bc75d-0d04-0410-961f-82ee72b054a4