[mlir] Fix assert on signed integer type in EDSC

[dcaballe]

Summary

Integer types in Std dialect are signless so we should be checking
for signless integer type instead of signed integer type in EDSC.

Authored by Adam Straw <[e-mail]>

mlir/lib/Dialect/Affine/EDSC/Builders.cpp

static ValueHandle createBinaryHandle(
   if (thisType.isIndex()) {
     return createBinaryIndexHandle(lhs, rhs, affCombiner);
   } else if (thisType.isSignlessInteger()) {
     return createBinaryHandle<IOp>(lhs, rhs);
   } else if (thisType.isa<FloatType>()) {
     return createBinaryHandle<FOp>(lhs, rhs);
   } else if (thisType.isa<VectorType>() || thisType.isa<TensorType>()) {
     auto aggregateType = thisType.cast<ShapedType>();
-    if (aggregateType.getElementType().isSignedInteger())
+    if (aggregateType.getElementType().isSignlessInteger())
       return createBinaryHandle<IOp>(lhs, rhs);
     else if (aggregateType.getElementType().isa<FloatType>())
       return createBinaryHandle<FOp>(lhs, rhs);
   }
   llvm_unreachable("failed to create a ValueHandle");
 }
 
 ValueHandle mlir::edsc::op::operator+(ValueHandle lhs, ValueHandle rhs) {

 
 static ValueHandle createIComparisonExpr(CmpIPredicate predicate,
                                          ValueHandle lhs, ValueHandle rhs) {
   auto lhsType = lhs.getType();
   auto rhsType = rhs.getType();
   (void)lhsType;
   (void)rhsType;
   assert(lhsType == rhsType && "cannot mix types in operators");
-  assert((lhsType.isa<IndexType>() || lhsType.isSignedInteger()) &&
+  assert((lhsType.isa<IndexType>() || lhsType.isSignlessInteger()) &&
          "only integer comparisons are supported");
 
   auto op = ScopedContext::getBuilder().create<CmpIOp>(
       ScopedContext::getLocation(), predicate, lhs.getValue(), rhs.getValue());
   return ValueHandle(op.getResult());
 }
 
 static ValueHandle createFComparisonExpr(CmpFPredicate predicate,