[clang] [sframe] Add assembler option --gsframe (PR #165322)

[Tarun Prabhu via cfe-commits]

https://github.com/tarunprabhu requested changes to this pull request.

Please add tests to check that:

- the option is passed on to cc1
- the correct error is emitted when an unsupported platform is used
- the assembler behaves as expected (even if this has been tested elsewhere, an end-to-end "integration" test would be useful)

https://github.com/llvm/llvm-project/pull/165322