[clang-tools-extra] Adding Separate OpenMP Offloading Backend to `libcxx/include/__algorithm/pstl_backends` (PR #66968)

[Louis Dionne via cfe-commits]

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ldionne wrote:

Not attached to this file: We should have simple documentation for this new backend somewhere in our `.rst` tree. It should explain what restrictions on user code are necessary when using this back-end, the behavior for exceptions, the fact that `-fopenmp` is required, etc.

And I expect that documentation can be a great place for us to discuss some design points of this backend :)

https://github.com/llvm/llvm-project/pull/66968