Implement 'this' calls.

lib/kernel_visitor.dart

Index: lib/kernel_visitor.dart
diff --git a/lib/kernel_visitor.dart b/lib/kernel_visitor.dart
index 0634e7b3c674445ae0e829d74098e8a5f90bab11..d3453dc00cda24b2150905c00cb83e9e9ead7d7c 100644
--- a/lib/kernel_visitor.dart
+++ b/lib/kernel_visitor.dart
@@ -2731,12 +2731,12 @@ class KernelVisitor extends Object
   }
 
   @override
-  ir.Throw visitThisInvoke(
+  ir.MethodInvocation visitThisInvoke(
       Send node,
       NodeList arguments,
       CallStructure callStructure,
       _) {
-    return buildUnsupported(node, "ThisInvoke");
+    return buildCall(new ir.ThisExpression(), callStructure, arguments);
   }
 
   Accessor buildThisPropertyAccessor(Name name) {
@@ -2976,16 +2976,6 @@ class KernelVisitor extends Object
     return new VariableDeclarations(variables);
   }
 
-  ir.Throw buildUnsupported(Node node, String name) {
-    // TODO(ahe): Do this:
-    // throw new Unsupported("Kernel IR not yet implemented for '$name'.");
-    if (const bool.fromEnvironment("verbose")) {
-      print("Kernel IR not yet implemented for '$name'.");
-    }
-    return new ir.Throw(
-        new ir.StringLiteral("Kernel IR not yet implemented for '$name'."));
-  }
-
   IrFunction buildFunction() {
     return kernel.compiler.reporter.withCurrentElement(currentElement, () {
       if (kernel.isSyntheticError(currentElement)) {