Auto merge of #4996 - alexcrichton:document-lto, r=matklad
authorbors <bors@rust-lang.org>
Wed, 31 Jan 2018 20:33:03 +0000 (20:33 +0000)
committerbors <bors@rust-lang.org>
Wed, 31 Jan 2018 20:33:03 +0000 (20:33 +0000)
Document string values for LTO


Trivial merge