Remove unnecessary uses of #[no_move]
The patch makes RootCollection a bit safer by making the StackRootTLS hold
it in place.
RootedVec was doing an extremely delicate dance and just hoping nobody
messed it up; switch to a Box to be safe.
CodeGenRust seemed to be using no_move for no particularly good reason.
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The patch makes RootCollection a bit safer by making the StackRootTLS hold
it in place.
The use of no_move in CodeGenRust was leftover from when roots couldn't
be moved.
This is necessary to ensure Cargo knows when to rebuild. Normally
.gitignore would be enough to exclude these from Cargo's freshness
calculation, but https://github.com/rust-lang/cargo/issues/1729 prevents
this currently. This is the new, correct way to do these thigns, just
like the style crate does.
