This leaves the `Share` trait at `std::kinds` via a `#[deprecated]` `pub use`
statement, but the `NoShare` struct is no longer part of `std::kinds::marker`
due to #12660 (the build cannot bootstrap otherwise).
All code referencing the `Share` trait should now reference the `Sync` trait,
and all code referencing the `NoShare` type should now reference the `NoSync`
type. The functionality and meaning of this trait have not changed, only the
naming.
Closes#16281
[breaking-change]
This breaks a fair amount of code. The typical patterns are:
* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;
* `println!("{}", 3)`: change to `println!("{}", 3i)`;
* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.
RFC #30. Closes#6023.
[breaking-change]
This is needed to make progress on #10296 as the default bounds will no longer
include Send. I believe that this was the originally intended syntax for procs,
and it just hasn't been necessary up until now.
