Auto merge of #43323 - perryprog:master, r=estebank
Less verbose output for unused arguments
Closes #37718
This is my first contribution to rust, so sorry if I'm missing anything!
The output now looks like this:
<img width="831" alt="screen shot 2017-07-18 at 5 01 32 pm" src="https://user-images.githubusercontent.com/12972285/28347566-dbfa9962-6c05-11e7-8730-c2e8062a04cc.png">
It's not the prettiest, but whenever #41850 gets resolved, this should be able to be improved.
**EDIT:** This also does not seem
r? @Mark-Simulacrum