Add help for target CPUs, features, relocation and code models.#34845
Merged
bors merged 10 commits intorust-lang:masterfrom Aug 11, 2016 
Merged
Add help for target CPUs, features, relocation and code models.#34845bors merged 10 commits intorust-lang:masterfrom 
bors merged 10 commits intorust-lang:masterfrom