[lto] Re-enable static-stdlib test now that we no longer LTO the target libraries.

rdar://26281388

Author: gottesmm

test/Driver/static-stdlib.swift

@@ -1,6 +1,5 @@
 // Statically link a "hello world" program
 // XFAIL: linux
-// REQUIRES: non_lto
 // REQUIRES: static_stdlib
 print("hello world!")
 // RUN: rm -rf %t && mkdir %t