[clang] [clang] Add support for -fcx-limited-range and #pragma CX_LIMITED_RANGE. (PR #68820)

[Zahira Ammarguellat via cfe-commits]

zahiraam wrote:

> I'm sure Aaron would appreciate me also saying that these changes would require addition to the clang release notes. 😄

Yes :-) Will do that. I just wanted you to have a first run through it.
I am getting a funny fail with the formatting as you can see. I think somehow my PR got corrupted so chances are I will create another PR and we can continue review there.  (unless you know how to solve the issue here?)

https://github.com/llvm/llvm-project/pull/68820