After testing `--pretty normal`, it tries to run `--pretty expanded` and
typecheck output.
Here we don't check convergence since it really diverges: for every
iteration, some extra lines (e.g.`extern crate std`) are inserted.
Some tests are `ignore-pretty`-ed since they cause various issues
with `--pretty expanded`.
This commit shreds all remnants of libextra from the compiler and standard
distribution. Two modules, c_vec/tempfile, were moved into libstd after some
cleanup, and the other modules were moved to separate crates as seen fit.
Closes#8784Closes#12413Closes#12576
When tests fail, their stdout and stderr is printed as part of the summary, but
this helps suppress failure messages from #[should_fail] tests and generally
clean up the output of the test runner.
fail!() used to require owned strings but can handle static strings
now. Also, it can pass its arguments to fmt!() on its own, no need for
the caller to call fmt!() itself.
