[clang] [Clang] Do not emit 'wchar' module flag for OpenCL (PR #174454)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> I think the language is the wrong question. The library functions are a property of the target ABI, not the language

But OpenCL doesn't support `wchar_t` at all from what I know, so this seems like the simplest way to remove this issue

https://github.com/llvm/llvm-project/pull/174454