folly: use -Wheader-hygiene with clang
authorIgor Sugak <sugak@fb.com>
Thu, 28 Jan 2016 00:12:47 +0000 (16:12 -0800)
committerfacebook-github-bot-0 <folly-bot@fb.com>
Thu, 28 Jan 2016 03:20:24 +0000 (19:20 -0800)
commit53edc275b70408e281b9a2a49be9d94762f77401
tree1346d81b48411c8430e13807b5993222f4e1bf1d
parent1ac421a539aaf2f349591d4bee36c75ff0ee052c
folly: use -Wheader-hygiene with clang

Summary: `-Wheader-hygiene` warns on using namespace directive in global context in header.  Fix all of the violations.

Reviewed By: yfeldblum

Differential Revision: D2867655

fb-gh-sync-id: 46840f8ece99e7af262058e631635d870bd51149
folly/io/async/test/AsyncSocketTest.h