std: add a Clone impl for HashSet.
Remove rtdebug_! and make rtdebug! work properly.

It now actually does logging, and is compiled out when `--cfg rtdebug` is not
given to the libstd build, which it isn't by default. This makes the rt
benchmarks 18-50% faster.
Remove in-tree test binary.

I presume this was accidentally committed.
Allow disabling optimizations in tests only
Fixed #8451 - extra::stats::write_boxplot() applied to negative or zero sample values
Fixed option_env! type

The type of the result of option_env! was not fully specified in the
None case, leading to type check failures in the case where the variable
was not defined (e.g. option_env!("FOO").is_none()).
Cleanup librustpkg a little bit.

Mostly I did simple transformations from imperative style loops to
more functional iterator based transformations.
remove more dead code from the old `for`
doc: Add -M and -L option to po4a
doc: Update .pot files
doc: Generate .po files for Japanse translations
tutorial: Add Japanese translation
Don't use unkillable in UnsafeArc dtor when there's no unwrapper. Close #8382.
Reorganise Select traits to not expose internal runtime types. Close #5160. Pending #8215.
Make cell with_ref/with_mut_ref use finally. Close #7975.
Fix select() in light of the deschedule...and then race. Close #8347.
Clean up transitionary glue in task/spawn.rs. Don't hold kill-little-lock for O(n) time, cf #3100, and optimize out several unneeded clone()s.
rt::task: Make current_stack_segment public

Servo needs to tell SpiderMonkey about the stack bounds.
register snapshots
fix build with the new snapshot compiler