Add comment referring to microsoft/DirectXShaderCompiler#7279 as the reason we don't use spirv intrinsics for ignoreIntersection and terminateRay

Author: kevyuu

71_RayTracingPipeline/app_resources/raytrace.rahit.hlsl

@@ -13,6 +13,7 @@ void main(inout PrimaryPayload payload, in BuiltInTriangleIntersectionAttributes
     const STriangleGeomInfo geom = vk::RawBufferLoad < STriangleGeomInfo > (pc.triangleGeomInfoBuffer + instID * sizeof(STriangleGeomInfo));
 
     const uint32_t bitpattern = payload.pcg();
+    // Cannot use spirv::ignoreIntersectionKHR and spirv::terminateRayKHR due to https://github.com/microsoft/DirectXShaderCompiler/issues/7279
     if (geom.material.alphaTest(bitpattern))
         IgnoreHit();
 }

71_RayTracingPipeline/app_resources/raytrace_shadow.rahit.hlsl

@@ -16,6 +16,9 @@ void main(inout OcclusionPayload payload, in BuiltInTriangleIntersectionAttribut
     const float attenuation = (1.f-material.alpha) * payload.attenuation;
     // DXC cogegens weird things in the presence of termination instructions
     payload.attenuation = attenuation;
+
+
+    // Cannot use spirv::ignoreIntersectionKHR and spirv::terminateRayKHR due to https://github.com/microsoft/DirectXShaderCompiler/issues/7279
     // arbitrary constant, whatever you want the smallest attenuation to be. Remember until miss, the attenuatio is negative
     if (attenuation > -1.f/1024.f)
         AcceptHitAndEndSearch();