[HLSL] Implement `SpirvType` and `SpirvOpaqueType` (#134034)

This implements the design proposed by [Representing SpirvType in
Clang's Type System](https://github.com/llvm/wg-hlsl/pull/181). It
creates `HLSLInlineSpirvType` as a new `Type` subclass, and
`__hlsl_spirv_type` as a new builtin type template to create such a
type.

This new type is lowered to the `spirv.Type` target extension type, as
described in [Target Extension Types for Inline SPIR-V and Decorated
Types](https://github.com/llvm/wg-hlsl/blob/main/proposals/0017-inline-spirv-and-decorated-types.md).

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/AST/ASTStructuralEquivalence.cpp b/clang/lib/AST/ASTStructuralEquivalence.cpp
index 499854a..47c8812 100644
--- a/clang/lib/AST/ASTStructuralEquivalence.cpp
+++ b/clang/lib/AST/ASTStructuralEquivalence.cpp
@@ -1157,6 +1157,23 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
       return false;
     break;
 
+  case Type::HLSLInlineSpirv:
+    if (cast<HLSLInlineSpirvType>(T1)->getOpcode() !=
+            cast<HLSLInlineSpirvType>(T2)->getOpcode() ||
+        cast<HLSLInlineSpirvType>(T1)->getSize() !=
+            cast<HLSLInlineSpirvType>(T2)->getSize() ||
+        cast<HLSLInlineSpirvType>(T1)->getAlignment() !=
+            cast<HLSLInlineSpirvType>(T2)->getAlignment())
+      return false;
+    for (size_t I = 0; I < cast<HLSLInlineSpirvType>(T1)->getOperands().size();
+         I++) {
+      if (cast<HLSLInlineSpirvType>(T1)->getOperands()[I] !=
+          cast<HLSLInlineSpirvType>(T2)->getOperands()[I]) {
+        return false;
+      }
+    }
+    break;
+
   case Type::Paren:
     if (!IsStructurallyEquivalent(Context, cast<ParenType>(T1)->getInnerType(),
                                   cast<ParenType>(T2)->getInnerType()))