Kernel prepatch 5.12-rc7

The 5.12-rc7 kernel prepatch is out; it's
rather larger than Linus would have liked.
'End result: I'm still waffling about the final 5.12 release. The fact
that we have a big rc7 does make me think that I'll probably do an rc8
this time around. But it ends up depending a bit on how the upcoming
week goes, and if things are deathly quiet, I may end up deciding that
an rc8 doesn't really make sense.'