cluster acceleration structure optix 6431 (#7028)

* Add cluster geometry intrinsics for ray tracing

- Added GetClusterID() method to HitObject class
- Added CandidateClusterID() and CommittedClusterID() methods to
RayQuery class
- Added SPV_NV_cluster_acceleration_structure extension support
- Added GL_NV_cluster_acceleration_structure extension support
- Added test files for RayQuery and HitObject cluster methods

Fixes #6431

* OpRayQueryGetIntersectionClusterIdNV - unrecognized spirv
Disabling spirv backend for SPV_NV_cluster_acceleration_structure

hlsl.meta.slang(18674): error 29100: unrecognized spirv opcode:
OpRayQueryGetIntersectionClusterIdNV
                result:$$int = OpRayQueryGetIntersectionClusterIdNV
&this $iCandidateOrCommitted;
                ^~~~~~
hlsl.meta.slang(18670): error 30019: expected an expression of type
'int', got 'void'
            return spirv_asm
                   ^~~~~~~~~
ninja: build stopped: subcommand failed.

* 6431 - Fix spirv opcode

* Remove tests

* Add relevant tests

* Review - Simplify tests

1 files changed, 29 insertions, 0 deletions

diff --git a/source/slang/glsl.meta.slang b/source/slang/glsl.meta.slang
index 00ad88add..05cef836c 100644
--- a/source/slang/glsl.meta.slang
+++ b/source/slang/glsl.meta.slang
@@ -4893,6 +4893,35 @@ public property uint gl_HitKindEXT
     }
 }
 
+public property int gl_ClusterIDNV
+{
+    [require(glsl_spirv, raytracing_anyhit_closesthit)]
+    get
+    {
+        setupExtForRayTracingBuiltIn();
+        __target_switch
+        {
+        case glsl:
+        {
+            __requireTargetExtension("GL_NV_cluster_acceleration_structure");
+            __intrinsic_asm "(gl_ClusterIDNV)";
+        }
+        case spirv:
+        {
+            return spirv_asm
+            {
+                OpCapability RayTracingClusterAccelerationStructureNV;
+                OpExtension "SPV_NV_cluster_acceleration_structure";
+                result:$$int = OpLoad builtin(ClusterIDNV:int);
+            };
+        }
+        }
+    }
+}
+// Constant to indicate that a cluster acceleration structure was not hit.
+// Corresponds to VK_GEOMETRY_INSTANCE_CLUSTER_ID_NONE_NV in Vulkan
+public static const int gl_ClusterIDNoneNV = -1;
+
 public property mat4x3 gl_ObjectToWorldEXT 
 {
     [require(glsl_spirv, raytracing_anyhit_closesthit_intersection)]