Begin writing tests of the runtime checks needed for Dart 2.0 soundness.

pkg/front_end/testcases/runtime_checks/dynamic_invocation.dart.direct.expect

+library test;
+import self as self;
+import "dart:core" as core;
+
+class C<T extends core::Object> extends core::Object {
+  default constructor •() → void
+    : super core::Object::•()
+    ;
+  method f1(self::C::T x) → void {}
+  method f2(core::int x) → void {}
+}
+class D extends self::C<core::num> {
+  default constructor •() → void
+    : super self::C::•()
+    ;
+  method f1(core::int x) → void {}
+}
+static method g1(dynamic d) → void {
+  d.f1(1.5);
+}
+static method g2(dynamic d) → void {
+  d.f2(1.5);
+}
+static method test() → void {
+  self::g1(new self::C::•<core::int>());
+  self::g2(new self::C::•<dynamic>());
+  self::g1(new self::D::•());
+}
+static method main() → dynamic {}