[kernel] Support for top-level generic functions.

pkg/kernel/lib/transformations/closure/rewriter.dart

Index: pkg/kernel/lib/transformations/closure/rewriter.dart
diff --git a/pkg/kernel/lib/transformations/closure/rewriter.dart b/pkg/kernel/lib/transformations/closure/rewriter.dart
index 3f4d0d3910623b206461687963df5426f2df342a..a76a938fec40634d76e4522523dc3d6a1adf613f 100644
--- a/pkg/kernel/lib/transformations/closure/rewriter.dart
+++ b/pkg/kernel/lib/transformations/closure/rewriter.dart
@@ -30,9 +30,10 @@ abstract class AstRewriter {
   void _createDeclaration() {
     assert(contextDeclaration == null && vectorCreation == null);
 
-    // Context size is set to 1 initially, because the 0-th element of it works
-    // as a link to the parent context.
-    vectorCreation = new VectorCreation(1);
+    // Context size is set to 2 initially, because the 1-st element of it holds
+    // the vector of type arguments that the VM creates, and the 0-th element
+    // works as a link to the parent context.
+    vectorCreation = new VectorCreation(2);
     contextDeclaration = new VariableDeclaration.forValue(vectorCreation,
         type: new VectorType());
     contextDeclaration.name = "#context";
@@ -74,9 +75,9 @@ class BlockRewriter extends AstRewriter {
     _createDeclaration();
     _insertStatement(contextDeclaration);
     if (accessParent is! NullLiteral) {
-      // Index 0 of a context always points to the parent.
+      // Index 1 of a context always points to the parent.

[jensj, 2017/08/11 06:24:54]

As I read it there's an inconsistency here: Here you say that index 1 is the
parent. Above you say "the 0-th element works as a link to the parent context."
(vs "the 1-st element of it holds the vector of type arguments")

[sjindel, 2017/08/11 09:21:06]

Good catch, I forgot to update the comment above.

       _insertStatement(new ExpressionStatement(
-          new VectorSet(new VariableGet(contextDeclaration), 0, accessParent)));
+          new VectorSet(new VariableGet(contextDeclaration), 1, accessParent)));
     }
   }