[dart2js] Indirect Uint8List(0) as List<int> not optimized

[rakudrama]

Source:

import 'dart:typed_data';

class Check {
  List<int> check(Object list) => list as List<int>;
}

main() {
  print(Check().check(Uint8List(5)));
}

Output:

    main() {
      A.printString(A.S(type$.List_int._as(new Uint8Array(5))));
    }

Global type inference determines that list is a NativeUint8List.
Inlining brings the typed list adjacent to the check.
Either should be sufficient to determine that the as-check always passes.

B5
r27 ForeignCode : Instance of 'New' (i3] [exact=NativeUint8List]    
r30 TypeKnown : r27 is [subclass=Object] [exact=NativeUint8List]    
v32 LoadType : TypeExpressionRecipe(List<int>)   [null|subclass=Object]    
r33 AsCheck : CastError v32, r30 [exact=NativeUint8List]    
s36 Stringify : r33 [exact=JSString] ! ? 
c38 Goto : (B6)]