[OpenMP] Make sure classes work on the device as they do on the host

We do provide `operator delete(void*)` in `<new>` but it should be
available by default. This is mostly boilerplate to test it and the
unconditional include of `<new>` in the header we always in include
on the device.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D100620