Add Mesh and Task shader support to GFX (#3190)

* Bump vulkan headers

Also just use vulkan-headers as a submodule

* Add drawMeshTasks to gfx graphics pipelines

* Add DispatchMesh overload with no payload, with GLSL intrinsic

* Require spirv 1.4 for mesh shaders

* Add vulkan mesh shader feature discovery

* Add mesh shader stage bits to vk-util

* Add mesh and task shader support to render-test

* Add mesh and task tests

* Preserve "payload" specifier in task shaders

* Add mesh shader pipeline support to gfx

* Add TODO

* Add numThreads attribute for amplification stage

* Add payload to task shader test

* Drop dependency on d3dx12

* Allow passing payloads from task to mesh shaders

* regenerate vs projects

* check DispatchMesh name correctly

* Add mesh shader tests to failing tests

* Detect wave-ops feature on vulkan

* Add fuse-product to expected failures

This fails because the global varaible `count` is not initialized

* Add required extension to WaveMaskMatch SPIR-V impl

* Remove meshShader member from pipeline desc

* Identify mesh shader support on d3d12

1 files changed, 14 insertions, 1 deletions

diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index 4266b46f9..106e5b5a3 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -1355,7 +1355,10 @@ static void addLinkageDecoration(
         }
         else if (as<KnownBuiltinAttribute>(modifier))
         {
-            builder->addKnownBuiltinDecoration(inst, decl->getName()->text.getUnownedSlice());
+            // We add this to the internal instruction, like other name-like
+            // decorations, for instance "nameHint". This prevents it becoming
+            // lost during specialization.
+            builder->addKnownBuiltinDecoration(inInst, decl->getName()->text.getUnownedSlice());
         }
     }
     if (as<InterfaceDecl>(decl->parentDecl) &&
@@ -2110,6 +2113,10 @@ void addVarDecorations(
         {
             builder->addFormatDecoration(inst, formatAttr->format);
         }
+        else if(auto payloadMod = as<HLSLPayloadModifier>(mod))
+        {
+            builder->addSimpleDecoration<IRHLSLMeshPayloadDecoration>(inst);
+        }
 
         // TODO: what are other modifiers we need to propagate through?
     }
@@ -2977,6 +2984,12 @@ void _lowerFuncDeclBaseTypeInfo(
             irParamType = builder->getRateQualifiedType(builder->getGroupSharedRate(), irParamType);
         }
 
+        // The 'payload' parameter is a read-only groupshared value
+        if(paramInfo.decl && paramInfo.decl->hasModifier<HLSLPayloadModifier>())
+        {
+            irParamType = builder->getRateQualifiedType(builder->getGroupSharedRate(), irParamType);
+        }
+
         paramTypes.add(irParamType);
     }