Implement matching on enumerations

[perost]

I fixed the type system to allow enum variables inside metarecords in r23571, but there is no support for using enumerations in patterns yet. It seems only simple identifiers are allowed right now, so matching against an enumeration literal gives an invalid pattern error. Example:

type E = enumeration(one, two, three);

uniontype U
  record R
    E e;
  end R;
end U;

function test
protected
  U u = R(E.one);
algorithm
  _ := match u
    case R(E.one) then ();
    else fail();
  end match;
end test;

[sjoelund.se]

A little related to #3005 since enumeration literals are constant identifiers

[sjoelund.se]

This is already working

[sjoelund.se]

Milestone renamed

[sjoelund.se]

Milestone renamed