Fix broken documentation link
Add regression test for #18566
Add optional messages to the unreachable macro.

Closes #18842.
Set exceeding bitshifts lint to deny

Discussed in #18587
time: Deprecate the library in the distribution

This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:

    [dependencies.time]
    git = "https://github.com/rust-lang/time"

To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.

Due to the deprecation of the in-tree crate, this is a:

[breaking-change]

cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented
auto merge of #18830 : adaszko/rust/patch-1, r=steveklabnik
Register new snapshots
auto merge of #18907 : alexcrichton/rust/snapshots, r=jakub-,jakub
auto merge of #18858 : alexcrichton/rust/remove-time, r=jakub

This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:

    [dependencies.time]
    git = "https://github.com/rust-lang/time"

To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.

Due to the deprecation of the in-tree crate, this is a:

[breaking-change]

cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented
auto merge of #18862 : murarth/rust/issue-18566-test, r=alexcrichton
auto merge of #18867 : michaelsproul/rust/unreachable-formatting, r=pcwalton

Closes #18842.
auto merge of #18872 : hirschenberger/rust/master, r=thestinger

Discussed in #18587