Alias to member of field doesn't work inside method

[ntrel]

Support for an alias aggregate type member resolving to a member of a field was added in #20610. However, that only seems to work outside the aggregate type. In particular:

struct Foo
{
    int v;
}

struct Bar
{
    Foo f;
    alias v = f.v;

    void test()
    {
        assert(v == 3); // error, requires an instance of Foo
        alias w = f.v;
        w++; // error, requires an instance of Foo
    }
}

Walter then mentioned ambiguities and trouble: #20610 (comment)

Unless all cases like #17532 are to be supported, I'm thinking fixing #20610 just confuses things.

Edition error

Another problem is that before #20610 was fixed, I made a PR for the next edition to detect aliases like v and w and error: #15863. If the #20610 fix should stay, the edition error needs tweaking (one of the cases is still needed). I looked at allowing #20610 but for some reason an alias declaration in a function is getting a null from toParent, not a FuncDeclaration.