Remove const fix for `const_with_undefined_constructor`

[FMorschel]

Repro:

enum E { v }

E e = const E.v; // const_with_undefined_constructor

The above triggers const_with_undefined_constructor on v. We could add a Remove 'const' quick-fix for this case.

[bwilkerson]

We could.

What would be ideal, imo, is for the analyzer to produce a different diagnostic in this case and for that diagnostic to have the "Remove 'const'" fix. The current message reads:

The class 'E' doesn't have a constant constructor 'v'.

It would be better if we told the user the v is an enum constant (or whatever it might be in other cases) and that const can only be used with invocations of const constructors.