Method markExplicitUnsigned

Many languages can mark an integer constant as explicitly \e unsigned. When the decompiler is deciding on \e cast operations, this is one of the checks it performs. This method checks if the indicated input is an integer constant that needs to be coerced (as a source token) into being unsigned. If this is \b true, the input Varnode is marked for printing as explicitly \e unsigned. \param op is th