Add primitive to create closures and use it for closure conversion

pkg/kernel/lib/ast.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// -----------------------------------------------------------------------
 ///                           ERROR HANDLING
 /// -----------------------------------------------------------------------
 ///
 /// As a rule of thumb, errors that can be detected statically are handled by
 /// the frontend, typically by translating the erroneous code into a 'throw' or
@@ skipping 2837 matching lines @@
       vectorExpression = vectorExpression.accept(v);
       vectorExpression?.parent = this;
     }
   }
 
   DartType getStaticType(TypeEnvironment types) {
     return const VectorType();
   }
 }
 
+/// Expression of the form `MakeClosure(f, c, t)` where `f` is a name of a
+/// closed top-level function, `c` is a Vector representing closure context, and
+/// `t` is the type of the resulting closure.
+class ClosureCreation extends Expression {
+  String topLevelFunctionName;

[asgerf, 2017/03/31 11:03:52]

Again, please use a reference to the member

[Dmitry Stefantsov, 2017/03/31 11:54:13]

Done.

+  Expression contextVector;
+  FunctionType functionType;
+
+  ClosureCreation(
+      this.topLevelFunctionName, this.contextVector, this.functionType) {
+    contextVector?.parent = this;
+  }
+
+  accept(ExpressionVisitor v) => v.visitClosureCreation(this);
+  accept1(ExpressionVisitor1 v, arg) => v.visitClosureCreation(this, arg);
+
+  visitChildren(Visitor v) {
+    contextVector?.accept(v);
+  }
+
+  transformChildren(Transformer v) {
+    if (contextVector != null) {
+      contextVector = contextVector.accept(v);
+      contextVector?.parent = this;
+    }
+  }
+
+  DartType getStaticType(TypeEnvironment types) {
+    return functionType;
+  }
+}
+
 // ------------------------------------------------------------------------
 //                              STATEMENTS
 // ------------------------------------------------------------------------
 
 abstract class Statement extends TreeNode {
   accept(StatementVisitor v);
   accept1(StatementVisitor1 v, arg);
 }
 
 /// A statement with a compile-time error.
@@ skipping 1364 matching lines @@
 /// library has not been assigned a canonical name yet.
 ///
 /// Returns `null` if the library is `null`.
 CanonicalName getCanonicalNameOfLibrary(Library library) {
   if (library == null) return null;
   if (library.canonicalName == null) {
     throw '$library has no canonical name';
   }
   return library.canonicalName;
 }