Reserve additional keywords

[axic]

const, immutable (#715), mutable, promise

[axic]

@federicobond suggested to reserve override to introduce the explicit override keyword on inherited, but locally declared state variables and functions.

[axic]

auto from #2558.

[axic]

final and sealed from #463.

[axic]

alias, typedef, define, macro from #1013.

[axic]

topic from #1241.

[chriseth]

Potentially apply and using for modifier areas.

[axic]

sizeof perhaps

[chriseth]

unchecked, so that we can disable the SMT checker for certain parts of the code, especially hand-crafted assembly (rust and c# have a similar feature).

[axic]

reference for variable references

[axic]

constructor from #3196 and fallback from #3198

[chriseth]

@axic do we want to reserve all of these above?

[axic]

I don't think any of them is particularly common in current use, though we could say auto can be removed from the above list since we deprecated var. Maybe it will be useful for something else, so would also consider keeping it.

[axic]

implements and/or supports from #2330

[chriseth]

Can this be closed?

[axic]

Why?

[chriseth]

Ah sorry, my bad.

[axic]

partial from #649