[CUDA] Forward sanitizer support to host toolchain

Summary:
This is an improvement on rL288448 where address sanitization was listed
as supported for the CudaToolChain. Since the intent is for the
CudaToolChain not to reject any flags supported by the host compiler,
this patch switches to forwarding the CudaToolChain sanitizer support to
the host toolchain rather than explicitly whitelisting address
sanitization.

Thanks to hfinkel for this suggestion.

Reviewers: jlebar

Subscribers: hfinkel, cfe-commits

Differential Revision: https://reviews.llvm.org/D27351

llvm-svn: 288512