Add an explicit -std=c++14 to this test.
Add an explicit -std=c++14 to this test.

rdar://problem/45642490

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@346048 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit aeae6c39e02255585227b64be2e7ea27fd11e1c9)

apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang