[clang] [Clang][Driver] Enable offloadlib option for clang-cl (PR #162980)

[Srividya Sundaram via cfe-commits]

srividya-sundaram wrote:

> @srividya-sundaram, are you okay with this PR?

Yes, the changes look good to me.
Just 1 clarifying question.

https://github.com/llvm/llvm-project/pull/162980