[clang] [C11] Claim conformance to WG14 N1396 (PR #101214)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> I mentioned this offline, but worth repeating here: I feel _something_ needs to be marked as partial/no for the x87 case. Aaron suggested Annex F support be that value rather than this paper, which I guess satisfies that.

Agreed; the way I'd like to proceed is to land this (once folks are happy with it) and set the status here to conforming, then update the entry for "IEC 60559 support" (under C99, which is already marked as `Partial`) to mention 32-bit x86 as another reason why we only partially conform. Does that sound reasonable?

https://github.com/llvm/llvm-project/pull/101214