[clang] [clang-tools-extra] Remove ^^ as a token in OpenCL (PR #108224)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> The changes to the lexer look fine.
> 
> I do have a question though Both the OpenCL 3.0 2.0 "C language specification" mention "^^ as being reserved" (https://registry.khronos.org/OpenCL/specs/3.0-unified/html/OpenCL_API.html)
> 
> However it does not appear to be the case - in the OpenCL 2.0 specification for c++ https://registry.khronos.org/OpenCL/specs/2.2/html/OpenCL_Cxx.html and it is not clear to me what the support in 3.0 is supposed to be ( no mention in https://github.com/KhronosGroup/Khronosdotorg/blob/main/api/opencl/assets/CXX_for_OpenCL.pdf )

I think I need @AnastasiaStulova to weigh in on that one, good catch!

https://github.com/llvm/llvm-project/pull/108224