Pull in r229281 from upstream libc++ (by Larisse Voufo):

Pull in r229281 from upstream libc++ (by Larisse Voufo):

  Implement C++14's sized deallocation functions, since there are no
  longer implicitly defined by clang, as of r229241.

This allows ports which use C++14's sized deallocation functions, such
as cad/openvsp, to build on stable/10.  Bump __FreeBSD_version to allow
detection from ports.

Direct commit, since stable/11 and head already have newer versions of
libc++ which include this change.

PR:		219484

git-svn-id: svn://svn.freebsd.org/base/stable/10@321222 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f