Change how unresolved super sends are handled.

pkg/front_end/testcases/inference/unresolved_super.dart.direct.expect

 library test;
 import self as self;
 import "dart:core" as core;
 
 class C extends core::Object {
   constructor •() → void
     : super core::Object::•()
     ;
   method test() → void {
-    dynamic v1 = super.noSuchMethod(new core::_InvocationMirror::•("foo", <dynamic>[0, 2, 2].toList(growable: false), <dynamic>[this, self::f<dynamic>()].toList(growable: false), true));
-    dynamic v2 = super.noSuchMethod(new core::_InvocationMirror::•("get:bar", <dynamic>[0, 1, 1].toList(growable: false), <dynamic>[this].toList(growable: false), true));
+    dynamic v1 = super.foo(self::f<dynamic>());
+    dynamic v2 = super.bar;
     dynamic v3 = super.[](0);
-    dynamic v4 = let final dynamic #t1 = self::f<dynamic>() in let final dynamic #t2 = super.noSuchMethod(new core::_InvocationMirror::•("set:bar", <dynamic>[0, 2, 2].toList(growable: false), <dynamic>[this, #t1].toList(growable: false), true)) in #t1;
-    dynamic v5 = let final dynamic #t3 = 0 in let final dynamic #t4 = self::f<dynamic>() in let final dynamic #t5 = super.[]=(#t3, #t4) in #t4;
+    dynamic v4 = super.bar = self::f<dynamic>();
+    dynamic v5 = let final dynamic #t1 = 0 in let final dynamic #t2 = self::f<dynamic>() in let final dynamic #t3 = super.[]=(#t1, #t2) in #t2;
   }
 }
 static method f<T extends core::Object>() → self::f::T
   return null;
 static method main() → dynamic {}