Bug 690970, part 1: unmark gray read barrier for weak maps. r=billm a=lsblakk
Bug 690970, part 2: unmark gray read barrier for watchpoints. r=billm a=lsblakk
Bug 690970, part 3: fix black-gray edges in weak containers at start of CC. r=billm a=lsblakk
Bug 829430 - Use the right check for if we're GCing. r=billm a=lsblakk