Implement N3421; comparison predicates<void>

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@187357 91177308-0d34-0410-b5e6-96231b3b80d8
Add operator new[] to test.  Partial fix for valgrind warning in http://llvm.org/bugs/show_bug.cgi?id=16703.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@187358 91177308-0d34-0410-b5e6-96231b3b80d8