This is for compatibility with MSVC, which also marks them as const. This is a break-off of D54667 to try to get rid of some of the boilerplate from the patch.
Right, just for the type of this variables. I... thought we already fixed this? Or maybe I just filed the bug and never actually submitted code to fix it? Whatever, ship the fix and I'll worry about my own deja-vu some other time. lgtm