[mlir][tosa] fix crash when querying the rank of an unranked tensor.

[Peiming]

revert unintended changes.

[jpienaar]

Thanks, conservatively we can't say if it has so shouldn't flag as invalid, so LGTM.

mlir/lib/Dialect/Tosa/IR/TosaOps.cpp

Operation *TosaDialect::materializeConstant(OpBuilder &builder, Attribute value,
   return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 // TOSA Operator Verifiers.
 //===----------------------------------------------------------------------===//
 
 static bool hasZeroDimension(ShapedType shapedType) {
+  if (!shapedType.hasRank())
+    return false;
+
   auto rank = shapedType.getRank();
 
   for (int i = 0; i < rank; i++) {
     if (shapedType.isDynamicDim(i))
       continue;
     if (shapedType.getDimSize(i) == 0)
       return true;
   }