dartc fails test on implementing 2 generics

[DartBot]

This issue was originally filed by [email protected]

---

dartc is failing this test: Language/13_Types/4_Interface_Types_A11_t04.dart

/**
 * @­assertion A type T is more specific than a type S, written T << S, if T << U and U << S.
 * << is a partial order on types. T is a subtype of S, written T <: S, iff [⊥/Dynamic]T << S.
 * A type T may be assigned to a type S, written T <=> S, if either T <: S or S <: T .
 * @­description Checks that if type T is a subtype of S1 and S2 where S1 <: S<G1> and S2 <: S<G2> then
 * T is a subtype of S<G1> as well as S<G2> and every other supertype of S.
 * @­author iefremov
 * @­reviewer rodionov
 */

interface S<T> {}

interface S1 extends S<int> {}

interface S2 extends S<double> {}

class T implements S1, S2 {}

main() {
  Expect.isTrue(new T() is S<int>);
  Expect.isTrue(new T() is S<double>);
  Expect.isTrue(new T() is S<num>);
  Expect.isTrue(new T() is S<Object>);
  Expect.isTrue(new T() is S);
}

it gives this error:

$ dartc tests/co19/src/Language/13_Types/4_Interface_Types_A11_t04.dart
file:/home/zundel/dart-all/dart/tests/co19/src/Language/13_Types/4_Interface_Types_A11_t04.dart:17: Type variable 'T' is hiding 'CLASS T' at 4_Interface_Types_A11_t04.dart:T:23:7
    16:
    17: interface S<T> {}
file:/home/zundel/dart-all/dart/tests/co19/src/Language/13_Types/4_Interface_Types_A11_t04.dart:23: S<int> and S<double> are duplicated in the supertype graph
    22:
    23: class T implements S1, S2 {}

[kasperl]

Removed Area-Compiler label.
Added Area-Analyzer label.

[danrubel]

Added this to the M1 milestone.

[DartBot]

This comment was originally written by [email protected]

---

https://chromiumcodereview.appspot.com/10627017

---

Set owner to [email protected].
Added Duplicate label.
Marked as being merged into #3803.