[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, 2 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 0356952..e235756 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -283,6 +283,7 @@ TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) {
     case Type::Pipe:
     case Type::BitInt:
     case Type::HLSLAttributedResource:
+    case Type::HLSLInlineSpirv:
       return TEK_Scalar;
 
     // Complexes.
@@ -2473,6 +2474,7 @@ void CodeGenFunction::EmitVariablyModifiedType(QualType type) {
     case Type::ObjCInterface:
     case Type::ObjCObjectPointer:
     case Type::BitInt:
+    case Type::HLSLInlineSpirv:
       llvm_unreachable("type class is never variably-modified!");
 
     case Type::Elaborated: