Fix for A=<<1>>

[James Hague]

>What I observed in erl_scan.erl is that this kind of
>cheating is already done when matching "<<", ">>", ">=",
>"->", etc.

I thought the same thing, and I wouldn't have even tried to special-case
"=<<" if there already hadn't been support in the same function for
multi-character tokens like "=<".  But I agree with your concern, and I'm
curious how those are handled properly by erl_scan.