[clang] [CIR][CUDA] Add semantic surface reference type (PR #223013)

[Konstantinos Parasyris via cfe-commits]

================
@@ -401,6 +401,20 @@ def CIR_VPtrType : CIR_Type<"VPtr", "vptr", [
   }];
 }
 
+//===----------------------------------------------------------------------===//
+// CUDADeviceSurfaceType
+//===----------------------------------------------------------------------===//
+
+def CIR_CUDADeviceSurfaceType :
+    CIR_Type<"CUDADeviceSurface", "cuda_surface"> {
+  let summary = "CUDA device surface reference type";
+  let description = [{
+    `!cir.cuda_surface` represents a CUDA built-in surface reference in CIR.
+    The type preserves surface semantics at the CIR level and is lowered to
+    the target device representation during lowering to LLVM IR.
----------------
koparasy wrote:

I would like to see here NVPTX being mentioned. AFAIK this is not a general device convention, while other targets are not reaching to this type. Something among the lines of:

```
The type preserves surface semantics at the CIR level and lowers to the NVPTX
device-side handle representation (`i64`) during lowering to LLVM IR.
```

https://github.com/llvm/llvm-project/pull/223013