[patch] [libcxx] new/.cpp trivial warning fix.

[Joerg Sonnenberger]

On Fri, Oct 25, 2013 at 11:49:50AM +1300, G M wrote:
> Attached are some trivial fixes for MSVC that remove numerous warning
> distractions in <new> and new.cpp.
> VC doesn't fully support these constructs. The existing and new code will
> obsolete itself for compilers that don't need it.
> 
> More substantial changes to come in a later patch.

Can we move this whole #if dance into a single macro and reuse that?
Including the existing check that is.

Joerg