[mlir] Fix Visual Studio warnings

[stella.stamenova]

Summary

There are only a couple of warnings when compiling with VS on Windows. This fixes the last remaining warnings so that we can enable LLVM_ENABLE_WERROR on the mlir windows bot.

[rriddle]

mlir/lib/Conversion/MathToSPIRV/MathToSPIRV.cpp

60

1u? This looks identical to below.

[stella.stamenova]

mlir/lib/Conversion/MathToSPIRV/MathToSPIRV.cpp

60

You mean uint64_t(1u)? Or do you mean to use 1u because the statement below does?

The statement below is different (as it does a subtraction as well), so the Visual Studio compiler is happy with it.

[rriddle]

Thanks for fixing these!

mlir/lib/Conversion/MathToSPIRV/MathToSPIRV.cpp

60

I meant to use 1u, as that would make these consistent. Though maybe it's better to pull this out into a separate variable (to share)? It doesn't matter much to me either way, the comment was more in passing.

mlir/include/mlir/Support/InterfaceSupport.h

public:
   static InterfaceMap get() {
     // TODO: Use constexpr if here in C++17.
     constexpr size_t numInterfaces = num_interface_types_t<Types...>::value;
     if (numInterfaces == 0)
       return InterfaceMap();
 
     std::array<std::pair<TypeID, void *>, numInterfaces> elements;
     std::pair<TypeID, void *> *elementIt = elements.data();
+    (void)elementIt;
     (void)std::initializer_list<int>{
         0, (addModelAndUpdateIterator<Types>(elementIt), 0)...};
     return InterfaceMap(elements);
   }
 
   /// Returns an instance of the concept object for the given interface if it
   /// was registered to this map, null otherwise.
   template <typename T> typename T::Concept *lookup() const {

mlir/lib/Conversion/MathToSPIRV/MathToSPIRV.cpp

if (auto scalarType = copySignOp.getType().dyn_cast<FloatType>()) {
       floatType = vectorType.getElementType().cast<FloatType>();
     } else {
       return failure();
     }
 
     Location loc = copySignOp.getLoc();
     int bitwidth = floatType.getWidth();
     Type intType = rewriter.getIntegerType(bitwidth);
+    uint64_t intValue = uint64_t(1) << (bitwidth - 1);
 
     Value signMask = rewriter.create<spirv::ConstantOp>(
-        loc, intType, rewriter.getIntegerAttr(intType, (1u << (bitwidth - 1))));
+        loc, intType, rewriter.getIntegerAttr(intType, intValue));
     Value valueMask = rewriter.create<spirv::ConstantOp>(
-        loc, intType,
-        rewriter.getIntegerAttr(intType, (1u << (bitwidth - 1)) - 1u));
+        loc, intType, rewriter.getIntegerAttr(intType, intValue - 1u));
 
     if (auto vectorType = copySignOp.getType().dyn_cast<VectorType>()) {
       assert(vectorType.getRank() == 1);
       int count = vectorType.getNumElements();
       intType = VectorType::get(count, intType);
 
       SmallVector<Value> signSplat(count, signMask);
       signMask =