[clang] [clang-cl] Support /stdc:latest (PR #147284)

[Nikolas Klauser via cfe-commits]

philnik777 wrote:

You've got the same typo (?) in a bunch of places. You have `/stdc:latest` instead of `/std:clatest`. Same for `/std:c++latest`.

https://github.com/llvm/llvm-project/pull/147284