[SPIR-V] Allow built-in object types as arguments to SpirvType

There has been a validation error for passing in a built-in type to a
template since the first commit to DXC. This check exists to prevent
instances like this:

```
Texture2D<SamplerState> image;
```

When DXC was first created, users could not create their own templates,
and therefore having a generic check for this did not cause any
problems. However, now that HLSL 2021 allows users to create their own
templates, and inline SPIR-V lets users pass types in to the SpirvType
and SpirvOpaqueType templates in order to reference them, this is
causing problems.

This PR allows the SpirvType and SpirvOpaqueType templates to take
HLSL built-in types as arguments.

Fixes microsoft#6498

tools/clang/lib/Sema/SemaHLSL.cpp

@@ -4904,7 +4904,7 @@ class HLSLExternalSource : public ExternalSemaSource {
   }
 
   bool IsValidTemplateArgumentType(SourceLocation argLoc, const QualType &type,
-                                   bool requireScalar) {
+                                   bool requireScalar, bool allowObject) {
     if (type.isNull()) {
       return false;
     }
@@ -4929,7 +4929,7 @@ class HLSLExternalSource : public ExternalSemaSource {
       if (qt->isArrayType()) {
         const ArrayType *arrayType = qt->getAsArrayTypeUnsafe();
         return IsValidTemplateArgumentType(argLoc, arrayType->getElementType(),
-                                           false);
+                                           false, allowObject);
       } else if (objectKind == AR_TOBJ_VECTOR) {
         bool valid = true;
         if (!IsValidVectorSize(GetHLSLVecSize(type))) {
@@ -4964,9 +4964,12 @@ class HLSLExternalSource : public ExternalSemaSource {
         objectKind = ClassifyRecordType(recordType);
         switch (objectKind) {
         case AR_TOBJ_OBJECT:
-          m_sema->Diag(argLoc, diag::err_hlsl_objectintemplateargument) << type;
-          return false;
         case AR_TOBJ_COMPOUND: {
+          if (objectKind == AR_TOBJ_OBJECT && !allowObject) {
+            m_sema->Diag(argLoc, diag::err_hlsl_objectintemplateargument)
+                << type;
+            return false;
+          }
           const RecordDecl *recordDecl = recordType->getDecl();
           if (recordDecl->isInvalidDecl())
             return false;
@@ -4975,8 +4978,9 @@ class HLSLExternalSource : public ExternalSemaSource {
           bool result = true;
           while (begin != end) {
             const FieldDecl *fieldDecl = *begin;
-            if (!IsValidTemplateArgumentType(argLoc, fieldDecl->getType(),
-                                             false)) {
+            if (!IsValidTemplateArgumentType(
+                    argLoc, fieldDecl->getType(), false,
+                    allowObject && objectKind != AR_TOBJ_OBJECT)) {
               m_sema->Diag(argLoc, diag::note_field_type_usage)
                   << fieldDecl->getType() << fieldDecl->getIdentifier() << type;
               result = false;
@@ -5193,7 +5197,10 @@ class HLSLExternalSource : public ExternalSemaSource {
         QualType argType = arg.getAsType();
         // Skip dependent types.  Types will be checked later, when concrete.
         if (!argType->isDependentType()) {
-          if (!IsValidTemplateArgumentType(argSrcLoc, argType, requireScalar)) {
+          bool allowObject =
+              templateName == "SpirvType" || templateName == "SpirvOpaqueType";
+          if (!IsValidTemplateArgumentType(argSrcLoc, argType, requireScalar,
+                                           allowObject)) {
             // NOTE: IsValidTemplateArgumentType emits its own diagnostics
             return true;
           }

tools/clang/test/CodeGenSPIRV/spv.inline.type.hlsl

@@ -1,12 +1,8 @@
 // RUN: %dxc -T ps_6_0 -E main -fcgl  %s -spirv | FileCheck %s
 
-// TODO(6498): enable Array test when using `Texture2D` with an alias template of `SpirvType` is fixed
-// CHECK-TODO: %type_Array_type_2d_image = OpTypeArray %type_2d_image
-// template<typename SomeType>
-// using Array = vk::SpirvOpaqueType</* OpTypeArray */ 28, SomeType, 4>;
-
 // CHECK: %spirvIntrinsicType = OpTypeArray %type_2d_image %uint_4
-typedef vk::SpirvOpaqueType</* OpTypeArray */ 28, Texture2D, vk::integral_constant<uint, 4> > ArrayTex2D;
+template<typename SomeType>
+using Array = vk::SpirvOpaqueType</* OpTypeArray */ 28, SomeType, vk::integral_constant<uint, 4> >;
 
 // CHECK: %spirvIntrinsicType_0 = OpTypeInt 8 0
 using uint8_t [[vk::ext_capability(/* Int8 */ 39)]] = vk::SpirvType</* OpTypeInt */ 21, 8, 8, vk::Literal<vk::integral_constant<uint, 8> >, vk::Literal<vk::integral_constant<bool, false> > >;
@@ -15,8 +11,7 @@ using uint8_t [[vk::ext_capability(/* Int8 */ 39)]] = vk::SpirvType</* OpTypeInt
 
 void main() {
   // CHECK: %image = OpVariable %_ptr_Function_spirvIntrinsicType Function
-  // Array<Texture2D> image;
-  ArrayTex2D image;
+  Array<Texture2D> image;
 
   // CHECK: %byte = OpVariable %_ptr_Function_spirvIntrinsicType_0
   uint8_t byte;