Auto merge of #4275 - alexcrichton:revert-makeflags, r=alexcrichton
authorbors <bors@rust-lang.org>
Wed, 12 Jul 2017 21:17:06 +0000 (21:17 +0000)
committerbors <bors@rust-lang.org>
Wed, 12 Jul 2017 21:17:06 +0000 (21:17 +0000)
Don't set MAKEFLAGS for build scripts

Closes #4156
Closes rust-lang/rust#42635


Trivial merge