Fix uninitialized memoryOwner on unused DescriptorSet

In the Renderer, we call DescriptorSet::PrepareForSampling() on all
input descriptors, not only the ones used in the current draw pass.
Because of this, DescriptorSet::PrepareForSampling() might be called
on uninitialized descriptors. Before this CL:
https://swiftshader-review.googlesource.com/c/SwiftShader/+/57889
that memory used to be zeroed out, so that wasn't an issue, but now
the memoryOwner pointer may be used without being initialized. This
CL adds an initialization for the memoryOwner field on structures
which use it (SampledImageDescriptor and StorageImageDescriptor).

Bug: chromium:1260606
Change-Id: I41a02a8b652a48b790d8aacf16fd28d26e527336
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/58308
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Commit-Queue: Alexis Hétu <sugoi@google.com>

src/Vulkan/VkDescriptorSetLayout.cpp

diff --git a/src/Vulkan/VkDescriptorSetLayout.cpp b/src/Vulkan/VkDescriptorSetLayout.cpp
index 63a8a90..f839d6b 100644
--- a/src/Vulkan/VkDescriptorSetLayout.cpp
+++ b/src/Vulkan/VkDescriptorSetLayout.cpp
@@ -176,12 +176,44 @@
 			{
 				SampledImageDescriptor *imageSamplerDescriptor = reinterpret_cast<SampledImageDescriptor *>(mem);
 				imageSamplerDescriptor->samplerId = bindings[i].immutableSamplers[j]->id;
+				imageSamplerDescriptor->memoryOwner = nullptr;
 				mem += descriptorSize;
 			}
 		}
 		else
 		{
-			mem += bindings[i].descriptorCount * descriptorSize;
+			switch(bindings[i].descriptorType)
+			{
+			case VK_DESCRIPTOR_TYPE_SAMPLER:
+			case VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER:
+			case VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE:
+			case VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER:
+				for(uint32_t j = 0; j < bindings[i].descriptorCount; j++)
+				{
+					SampledImageDescriptor *imageSamplerDescriptor = reinterpret_cast<SampledImageDescriptor *>(mem);
+					imageSamplerDescriptor->memoryOwner = nullptr;
+					mem += descriptorSize;
+				}
+				break;
+			case VK_DESCRIPTOR_TYPE_STORAGE_IMAGE:
+			case VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER:
+			case VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT:
+				for(uint32_t j = 0; j < bindings[i].descriptorCount; j++)
+				{
+					StorageImageDescriptor *storageImage = reinterpret_cast<StorageImageDescriptor *>(mem);
+					storageImage->memoryOwner = nullptr;
+					mem += descriptorSize;
+				}
+				break;
+			case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER:
+			case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER:
+			case VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC:
+			case VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC:
+				mem += bindings[i].descriptorCount * descriptorSize;
+				break;
+			default:
+				UNSUPPORTED("Unsupported Descriptor Type: %d", int(bindings[i].descriptorType));
+			}
 		}
 	}
 }