[clang] [HLSL][NFC] Move IsIntangibleType from SemaHLSL to Type to make it accessible outside of Sema (PR #113206)

[Justin Bogner via cfe-commits]

https://github.com/bogner approved this pull request.

I'm a little bit worried about how subtle the naming difference is from when we want to talk about if the builtin itself is intangible or if the type is transitively intangible, but that might just be because we're replacing one name with the other in this change and maybe it's not so bad in practice.

In any case, this change seems correct and indeed NFC. LG.

https://github.com/llvm/llvm-project/pull/113206