There was a special case for ArrayHandleMultiplexer where if you gave it
just one type it would treat that as a value type rather than an array
to support and instead provide a default list of types. However, GCC 4.8
is having trouble compiling the code to create the default list, the
semantics are confusing, and the more I think about it the less likely I
think we will need this functionality. So, just getting rid of that.
