Remove/Update PIX tests checking for old RayDesc IR pattern

The PIX test or portion of test that relies on the old compiler behavior of alloca for RayDesc.
Since these tests were made specifically to verfify this old pattern, it was ok to remove them.

Author: tex3d

tools/clang/test/HLSLFileCheck/pix/AnnotateVirtualRegs-Raygen.hlsl

@@ -119,7 +119,6 @@ class PixTest : public ::testing::Test {
   TEST_METHOD(AccessTracking_ModificationReport_SM66)
 
   TEST_METHOD(PixStructAnnotation_Lib_DualRaygen)
-  TEST_METHOD(PixStructAnnotation_Lib_RaygenAllocaStructAlignment)
 
   TEST_METHOD(PixStructAnnotation_Simple)
   TEST_METHOD(PixStructAnnotation_CopiedStruct)
@@ -1455,100 +1454,6 @@ void Raygen1()
   }
 }
 
-TEST_F(PixTest, PixStructAnnotation_Lib_RaygenAllocaStructAlignment) {
-  if (m_ver.SkipDxilVersion(1, 5))
-    return;
-
-  const char *hlsl = R"(
-
-RaytracingAccelerationStructure Scene : register(t0, space0);
-RWTexture2D<float4> RenderTarget : register(u0);
-
-struct SceneConstantBuffer
-{
-    float4x4 projectionToWorld;
-    float4 cameraPosition;
-    float4 lightPosition;
-    float4 lightAmbientColor;
-    float4 lightDiffuseColor;
-};
-
-ConstantBuffer<SceneConstantBuffer> g_sceneCB : register(b0);
-
-struct RayPayload
-{
-    float4 color;
-};
-
-inline void GenerateCameraRay(uint2 index, out float3 origin, out float3 direction)
-{
-    float2 xy = index + 0.5f; // center in the middle of the pixel.
-    float2 screenPos = xy;// / DispatchRaysDimensions().xy * 2.0 - 1.0;
-
-    // Invert Y for DirectX-style coordinates.
-    screenPos.y = -screenPos.y;
-
-    // Unproject the pixel coordinate into a ray.
-    float4 world = /*mul(*/float4(screenPos, 0, 1)/*, g_sceneCB.projectionToWorld)*/;
-
-    //world.xyz /= world.w;
-    origin = world.xyz; //g_sceneCB.cameraPosition.xyz;
-    direction = float3(1,0,0);//normalize(world.xyz - origin);
-}
-
-void RaygenCommon()
-{
-    float3 rayDir;
-    float3 origin;
-    
-    // Generate a ray for a camera pixel corresponding to an index from the dispatched 2D grid.
-    GenerateCameraRay(DispatchRaysIndex().xy, origin, rayDir);
-
-    // Trace the ray.
-    // Set the ray's extents.
-    RayDesc ray;
-    ray.Origin = origin;
-    ray.Direction = rayDir;
-    // Set TMin to a non-zero small value to avoid aliasing issues due to floating - point errors.
-    // TMin should be kept small to prevent missing geometry at close contact areas.
-    ray.TMin = 0.001;
-    ray.TMax = 10000.0;
-    RayPayload payload = { float4(0, 0, 0, 0) };
-    TraceRay(Scene, RAY_FLAG_CULL_BACK_FACING_TRIANGLES, ~0, 0, 1, 0, ray, payload);
-
-    // Write the raytraced color to the output texture.
-   // RenderTarget[DispatchRaysIndex().xy] = payload.color;
-}
-
-[shader("raygeneration")]
-void Raygen()
-{
-    RaygenCommon();
-}
-)";
-
-  auto Testables = TestStructAnnotationCase(hlsl, L"-Od", true, L"lib_6_6");
-
-  // Built-in type "RayDesc" has this structure: struct { float3 Origin; float
-  // TMin; float3 Direction; float TMax; } This is 8 floats, with members at
-  // offsets 0,3,4,7 respectively.
-
-  auto FindAtLeastOneOf = [=](char const *name, uint32_t index) {
-    VERIFY_IS_TRUE(std::find_if(Testables.AllocaWrites.begin(),
-                                Testables.AllocaWrites.end(),
-                                [&name, &index](AllocaWrite const &aw) {
-                                  return 0 == strcmp(aw.memberName.c_str(),
-                                                     name) &&
-                                         aw.index == index;
-                                }) != Testables.AllocaWrites.end());
-  };
-
-  FindAtLeastOneOf("Origin.x", 0);
-  FindAtLeastOneOf("TMin", 3);
-  FindAtLeastOneOf("Direction.x", 4);
-  FindAtLeastOneOf("TMax", 7);
-}
-
 TEST_F(PixTest, PixStructAnnotation_Simple) {
   if (m_ver.SkipDxilVersion(1, 5))
     return;
@@ -3441,7 +3346,6 @@ void RaygenInternalName()
   // check that there are alloca writes that cover all of them. RayPayload
   // has four elements, and RayDesc has eight.
   std::array<bool, 4> RayPayloadElementCoverage;
-  std::array<bool, 8> RayDescElementCoverage;
 
   for (auto const &write : metaDataKeyToValue.allocaWrites) {
     // the whole point of the changes with this test is to separate vector
@@ -3452,14 +3356,10 @@ void RaygenInternalName()
     if (findAlloca != metaDataKeyToValue.allocaDefinitions.end()) {
       if (findAlloca->second.count == 4) {
         RayPayloadElementCoverage[write.second.offset] = true;
-      } else if (findAlloca->second.count == 8) {
-        RayDescElementCoverage[write.second.offset] = true;
       }
     }
   }
   // Check that coverage for every element was emitted:
   for (auto const &b : RayPayloadElementCoverage)
     VERIFY_IS_TRUE(b);
-  for (auto const &b : RayDescElementCoverage)
-    VERIFY_IS_TRUE(b);
 }