Rust 1.60.0 released

Version1.60.0 of the Rust language is available. Changes includecoverage-testing improvements, the return of incremental compilation, andchanges to the Instant type:

Prior to 1.60, the monotonicity guarantees were provided throughmutexes or atomics in std, which can introduce large performanceoverheads to Instant::now(). Additionally, the panicking behaviormeant that Rust software could panic in a subset of environments,which was largely undesirable, as the authors of that software maynot be able to fix or upgrade the operating system, hardware, orvirtualization system they are running on.