xfailed three tests

[catamorphism]

Test in rust.md beginning with impl: ~str: Printable, src/test/run-pass/stat.rs, and src/test/bench/shootout/n-body.rs

It's too late at night to figure out what's wrong :-)

[andrew-d]

I took a stab at this issue. Submitted #4181 to fix the example in the docs, and can't reproduce either of the other two test failures. Not sure how to just run specific tests, so I just compiled each into executables and ran them:

$ ./x86_64-apple-darwin/stage2/bin/rustc -Z verbose -o /tmp/test1 ./src/test/bench/shootout-nbody.rs
warning: no debug symbols in executable (-arch x86_64)
$ ./x86_64-apple-darwin/stage2/bin/rustc -Z verbose -o /tmp/test2 ./src/test/run-pass/stat.rs
warning: no debug symbols in executable (-arch x86_64)
$ cd /tmp
$ ./test1
-0.169075
-0.169080
$ ./test2
$

Feel free to correct if necessary :)

[catamorphism]

Thanks! For reference, you can run a specific test with:

make check TESTNAME=stat

(for example). There's lots more info at https://github.com/mozilla/rust/wiki/Note-testsuite

[catamorphism]

Indeed, stat and n-body seems to have fixed themselves. I love it when that happens.

Thanks for the pull request, @andrew-d !