Implement more super calls.

test/kernel/regression/super_operator.dart.txt

+library;
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  constructor •() → self::A
+    : super core::Object::•();
+  operator +(core::String s) → dynamic
+    return null;
+  index-get [](dynamic i) → dynamic
+    return null;
+  index-set []=(dynamic i, dynamic val) → dynamic {}
+}
+class B extends self::A {
+  constructor •() → self::B
+    : super self::A::•();
+  operator +(core::String s) → dynamic
+    return super.self::A::+("${s}${s}");
+  index-get [](dynamic i) → dynamic
+    return super.self::A::[](i);
+  index-set []=(dynamic i, dynamic val) → dynamic
+    return let final #t1 = let final #t2 = i in let final #t3 = i = #t2.+(1) in #t2 in super.self::A::[]=(#t1, super.self::A::[](#t1).+(val));
+}
+class Autobianchi extends core::Object {
+  constructor •() → self::Autobianchi
+    : super core::Object::•();
+  method g() → dynamic
+    return invalid-expression;
+}