HiPE has had metadata for gc safety on it's temporaries for a while, but
it has never been enforced or even checked, so naturally several
gc-safety violations has slipped through.

A new pass, hipe_rtl_verify_gcsafe verifies gcsafety on optimised RTL
and is used when running the testsuite, and can be manually enabled with
+{hipe,[verify_gcsafe]}.

The types array(), dict(), digraph(), gb_set(), gb_tree(), queue(),
set(), and tid() have been deprecated. They will be removed in OTP 18.0.

Instead the types array:array(), dict:dict(), digraph:graph(),
gb_set:set(), gb_tree:tree(), queue:queue(), sets:set(), and ets:tid()
can be used. (Note: it has always been necessary to use ets:tid().)

It is allowed in OTP 17.0 to locally re-define the types array(), dict(),
and so on.

New types array:array/1, dict:dict/2, gb_sets:set/1, gb_trees:tree/2,
queue:queue/1, and sets:set/1 have been added.