An inout(T) function parameter is represented as "NgT" (ie. Wild T, per the ABI).  'N' is already used as the signifier for a FuncAttr, so this function:

   nothrow inout(int) fn(inout(int) x) { return x; }

Is mangled as:

   2fnFNbNgiZNgi

Parsing this, I have to explicitly recognize "Ng" as not a FuncAttr but rather the beginning of an inout parameter type, rewind the parse location (admittedly by one char) and jump out of the FuncAttr parse loop to deal with it.  Couldn't some other label be used to mark an inout parameter so this conflict doesn't exist?  I guess TypeNewArray might have this same problem ("Ne") except that it isn't even used in D2 right now so I suppose that's a non-issue.