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

[Chris B via cfe-commits]

================
@@ -3228,6 +3228,62 @@ static QualType builtinCommonTypeImpl(Sema &S, TemplateName BaseTemplate,
   }
 }
 
+static bool isInVkNamespace(const RecordType *RT) {
+  DeclContext *DC = RT->getDecl()->getDeclContext();
+  if (!DC)
+    return false;
+
+  NamespaceDecl *ND = dyn_cast<NamespaceDecl>(DC);
+  if (!ND)
+    return false;
+
+  return ND->getQualifiedNameAsString() == "hlsl::vk";
+}
+
+static SpirvOperand checkHLSLSpirvTypeOperand(Sema &SemaRef,
+                                              QualType OperandArg,
+                                              SourceLocation Loc) {
+  if (auto *RT = OperandArg->getAs<RecordType>()) {
+    bool Literal = false;
+    SourceLocation LiteralLoc;
+    if (isInVkNamespace(RT) && RT->getDecl()->getName() == "Literal") {
+      auto SpecDecl = dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
+      assert(SpecDecl);
+
+      const TemplateArgumentList &LiteralArgs = SpecDecl->getTemplateArgs();
+      QualType ConstantType = LiteralArgs[0].getAsType();
+      RT = ConstantType->getAs<RecordType>();
+      Literal = true;
+      LiteralLoc = SpecDecl->getSourceRange().getBegin();
+    }
+
+    if (RT && isInVkNamespace(RT) &&
+        RT->getDecl()->getName() == "integral_constant") {
+      auto SpecDecl = dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
+      assert(SpecDecl);
+
+      const TemplateArgumentList &ConstantArgs = SpecDecl->getTemplateArgs();
+
+      QualType ConstantType = ConstantArgs[0].getAsType();
+      llvm::APInt Value = ConstantArgs[1].getAsIntegral();
+
+      if (Literal) {
+        return SpirvOperand::createLiteral(Value);
+      } else {
+        return SpirvOperand::createConstant(ConstantType, Value);
+      }
----------------
llvm-beanz wrote:

nit: [braces](https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements) & [else](https://llvm.org/docs/CodingStandards.html#don-t-use-else-after-a-return)

```suggestion
      if (Literal)
        return SpirvOperand::createLiteral(Value);
      return SpirvOperand::createConstant(ConstantType, Value);
```

https://github.com/llvm/llvm-project/pull/134034