noexcept for <memory>. I've added a few extension noexcept to: ...

noexcept for <memory>.  I've added a few extension noexcept to:  allocator_traits<A>::deallocate, allocaate<T>::deallocate, return_temporary_buffer, and default_delete<T>::operator()(T*) const.  My rationale was:  If a std-dicated noexcept function needs to call another std-defined function, that called function must be noexcept.  We're all a little new to noexcept, so things like this are to be expected.  Also included fix for broken __is_swappable trait pointed out by Marc Glisse, thanks Marc|.  And fixed a test case for is_nothrow_destructible.  Destructors are now noexcept by default|

llvm-svn: 132261