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

[Helena Kotas via cfe-commits]

================
@@ -5030,6 +5030,29 @@ bool Type::hasSizedVLAType() const {
   return false;
 }
 
+bool Type::isHLSLIntangibleType() const {
+  const Type *Ty = getUnqualifiedDesugaredType();
+
+  // check if it's a builtin type first (simple check, no need to cache it)
----------------
hekota wrote:

I've updated the comment.

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