Update VK_CBuffer_Zoo test to account for glslang regression

* glslang now requires and uses scalar block layout for hlsl cbuffer packing

util/test/demos/vk/vk_cbuffer_zoo.cpp

@@ -332,7 +332,8 @@ layout(set = 0, binding = 0) cbuffer consts
   float4 dummy1;
 
   float o[4];                             // should cover 4 float4s = 48, <..>, 52, <..>, 56, <..>, 60
-  float p;                                // can't be packed in with above array = 64, <65, 66, 67>
+  float p;                                // with glslang regression to scalar packing, is packed after = 61
+  float3 glslang_regression;
   float4 dummy2;
   float4 gldummy;
 
@@ -393,7 +394,8 @@ layout(set = 0, binding = 0) cbuffer consts
                                           // row1: {197, 201}
                                           //       <198, 202>
                                           //       <199, 203>
-  float z;                                // doesn't overlap in final row = 204, <205, 206, 207>
+  float z;                                // with glslang regression to scalar packing, is packed after = 202
+  float3 glslang_regression2;
 
   // SPIR-V can't represent single-dimension matrices properly at the moment
 /*
@@ -572,6 +574,10 @@ float4 main() : SV_Target0
     devExts.push_back(VK_KHR_RELAXED_BLOCK_LAYOUT_EXTENSION_NAME);
     optDevExts.push_back(VK_EXT_INLINE_UNIFORM_BLOCK_EXTENSION_NAME);
 
+    // new glslang has a regression that requires scalar block layout for hlsl and does not support
+    // generating non-scalar layout hlsl packing
+    devExts.push_back(VK_EXT_SCALAR_BLOCK_LAYOUT_EXTENSION_NAME);
+
     VulkanGraphicsTest::Prepare(argc, argv);
 
     static VkPhysicalDeviceInlineUniformBlockFeaturesEXT inlineFeats = {
@@ -584,6 +590,19 @@ float4 main() : SV_Target0
       inlineFeats.pNext = (void *)devInfoNext;
       devInfoNext = &inlineFeats;
     }
+
+    static VkPhysicalDeviceScalarBlockLayoutFeaturesEXT scalarFeatures = {
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SCALAR_BLOCK_LAYOUT_FEATURES_EXT,
+    };
+
+    getPhysFeatures2(&scalarFeatures);
+
+    if(!scalarFeatures.scalarBlockLayout)
+      Avail = "Scalar block layout feature 'scalarBlockLayout' not available";
+
+    scalarFeatures.pNext = (void *)devInfoNext;
+
+    devInfoNext = &scalarFeatures;
   }
 
   int main()

util/test/tests/Vulkan/VK_CBuffer_Zoo.py

@@ -529,8 +529,11 @@ class VK_CBuffer_Zoo(rdtest.TestCase):
             3: lambda x: x.rows(1).cols(1).value([60.0]),
         })
 
-        # float p; with std140 vulkan packing
-        var_check.check('p').rows(1).cols(1).value([64.0])
+        # float p; with forced scalar vulkan packing due to glslang regression
+        var_check.check('p').rows(1).cols(1).value([61.0])
+
+        # float3 glslang_regression;
+        var_check.check('glslang_regression')
 
         # float4 dummy2;
         var_check.check('dummy2')
@@ -608,7 +611,10 @@ class VK_CBuffer_Zoo(rdtest.TestCase):
                                                                    197.0, 201.0])
 
         # float z;
-        var_check.check('z').rows(1).cols(1).value([204.0])
+        var_check.check('z').rows(1).cols(1).value([202.0])
+
+        # float3 glslang_regression2;
+        var_check.check('glslang_regression2')
 
         # Temporarily until SPIR-V support for degenerate HLSL matrices is determined
         var_check.check('dummy9')