Polymorphic self reference does not work

[mlbrooks]

    forall( tE & )
    struct thing {
        thing(tE) *a;
        thing(tE) *b;
    };

Actual: cfa emits bad code: gcc reports parse errors

Expected: compiles (-c) successfully

Observation: cfa -CFA -XCFA,-p gives the fragment:

    struct thing {
        struct thing()  *_X1aPS5thing_Y13__tE_generic___1;
        struct thing *_X1bPS5thing_Y13__tE_generic___1;
    };

Note the field a has extra parentheses (bad C syntax)
Note the field b is being emitted correctly

The following convoluted sequence of declarations gives a workaround:

    struct nothing {};
    forall( tE & ) {
        struct nothing_poly {};
        struct thing;
        extern "C" {
            nothing xx(nothing_poly(tE)*);  // never defined
            foo(thing(tE)) * not_a_literal();  // never defined
        }
        struct thing{
            typeof(xx(not_a_literal())) shouldBeHarmless;
            thing(tE) *a;
            thing(tE) *b;
        };
    }