Auto merge of #2629 - alexcrichton:moar-rustflags, r=brson
authorbors <bors@rust-lang.org>
Sat, 30 Apr 2016 00:46:56 +0000 (17:46 -0700)
committerbors <bors@rust-lang.org>
Sat, 30 Apr 2016 00:46:56 +0000 (17:46 -0700)
Pass RUSTFLAGS when we learn about target info

This should help us learn about `target_feature` additions!

Closes #2628


Trivial merge