Fixed all warnings in the Vulkan build on Windows

There were a bunch of warnings on Windows:
- Precision loss through type conversion
- Switch statement containing only default case
- Zero sized array

Bug b/130335507

Change-Id: I809db29db16f5dfd62d03d40353f4f2e0f6c3c93
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28768
Tested-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>

src/Pipeline/PixelRoutine.cpp

diff --git a/src/Pipeline/PixelRoutine.cpp b/src/Pipeline/PixelRoutine.cpp
index 57cbf4e..2857fb3 100644
--- a/src/Pipeline/PixelRoutine.cpp
+++ b/src/Pipeline/PixelRoutine.cpp
@@ -509,8 +509,8 @@
 		Int4 zTest;
 
 		// Bias values to make unsigned compares out of Reactor's (due SSE's) signed compares only
-		zValue = zValue - Short4(0x8000);
-		Z = Z - Short4(0x8000);
+		zValue = zValue - Short4(0x8000u);
+		Z = Z - Short4(0x8000u);
 
 		switch(state.depthCompareMode)
 		{

src/Pipeline/SpirvShader.cpp

diff --git a/src/Pipeline/SpirvShader.cpp b/src/Pipeline/SpirvShader.cpp
index e0bcdff..2b6cbd8 100644
--- a/src/Pipeline/SpirvShader.cpp
+++ b/src/Pipeline/SpirvShader.cpp
@@ -942,7 +942,7 @@
 
 				auto set = routine->getPointer(id);
 				auto setLayout = routine->pipelineLayout->getDescriptorSetLayout(d.DescriptorSet);
-				size_t bindingOffset = setLayout->getBindingOffset(d.Binding, arrayIndex);
+				int bindingOffset = static_cast<int>(setLayout->getBindingOffset(d.Binding, arrayIndex));
 
 				Pointer<Byte> bufferInfo = Pointer<Byte>(set + bindingOffset); // VkDescriptorBufferInfo*
 				Pointer<Byte> buffer = *Pointer<Pointer<Byte>>(bufferInfo + OFFSET(VkDescriptorBufferInfo, buffer)); // vk::Buffer*
@@ -974,7 +974,7 @@
 		Decorations d = {};
 		ApplyDecorationsForId(&d, baseObject.type);
 
-		size_t arrayIndex = 0;
+		uint32_t arrayIndex = 0;
 		if (baseObject.kind == Object::Kind::DescriptorSet)
 		{
 			auto type = getType(typeId).definition.opcode();

src/Pipeline/SpirvShader_dbg.cpp

diff --git a/src/Pipeline/SpirvShader_dbg.cpp b/src/Pipeline/SpirvShader_dbg.cpp
index feacb87..3dd4e43 100644
--- a/src/Pipeline/SpirvShader_dbg.cpp
+++ b/src/Pipeline/SpirvShader_dbg.cpp
@@ -21,8 +21,8 @@
 {
 	std::string SpirvShader::OpcodeName(spv::Op op)
 	{
-		switch(op){
 #ifndef NDEBUG
+		switch(op){
 		case spv::OpNop: return "Nop";
 		case spv::OpUndef: return "Undef";
 		case spv::OpSourceContinued: return "SourceContinued";
@@ -399,10 +399,12 @@
 		case spv::OpDecorateStringGOOGLE: return "DecorateStringGOOGLE";
 		case spv::OpMemberDecorateStringGOOGLE: return "MemberDecorateStringGOOGLE";
 		case spv::OpMax: return "Max";
-#endif // NDEBUG
 		default:
-			return "Opcode<" + std::to_string(static_cast<int>(op)) + ">";
+			break;
 		}
+#endif // NDEBUG
+
+		return "Opcode<" + std::to_string(static_cast<int>(op)) + ">";
 	}
 
 } // namespace sw