Add support for converted closures with explicit contexts to VM

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

Index: pkg/kernel/lib/transformations/closure/converter.dart
diff --git a/pkg/kernel/lib/transformations/closure/converter.dart b/pkg/kernel/lib/transformations/closure/converter.dart
index e1865f7fd6d90a6c04a8e0dbeba37456490f612f..658dea8914dd8fd629eea358905acaf51ee5c676 100644
--- a/pkg/kernel/lib/transformations/closure/converter.dart
+++ b/pkg/kernel/lib/transformations/closure/converter.dart
@@ -230,6 +230,7 @@ class ClosureConverter extends Transformer {
       }
     }
     rewriter = null;
+    context = null;
     // Transform constructor body.
     FunctionNode function = node.function;
     if (function.body != null && function.body is! EmptyStatement) {
@@ -424,6 +425,8 @@ class ClosureConverter extends Transformer {
 
     FunctionNode function = node.function;
     if (function.body != null) {
+      bool hadSingleStatementBody = function.body is! Block;
+
       setupContextForFunctionBody(function);
       VariableDeclaration self = thisAccess[currentMemberFunction];
       if (self != null) {
@@ -431,6 +434,22 @@ class ClosureConverter extends Transformer {
       }
       node.transformChildren(this);
       resetContext();
+
+      // Here a special case is handled: the body of the procedure was a single
+      // statement and after the transformation it is a block with a single
+      // statement inside.  In this case we make this statement the body of the
+      // procedure again.  It is required to follow the conventions imposed by
+      // [addClass] in [DillLibraryBuilder].
+      // See [dill_library_builder.dart]
+      // (../../../../front_end/lib/src/fasta/dill/dill_library_builder.dart)
+      // for details.
+      if (hadSingleStatementBody && function.body is Block) {
+        Block body = function.body;
+        if (body.statements.length == 1) {
+          function.body = body.statements[0];
+          function.body.parent = function;
+        }
+      }
     }
 
     return node;
@@ -483,7 +502,7 @@ class ClosureConverter extends Transformer {
   TreeNode visitBlock(Block node) {
     return saveContext(() {
       BlockRewriter blockRewriter = rewriter = rewriter.forNestedBlock(node);
-      blockRewriter.transformStatements(node, this);
+      blockRewriter.transformStatements(this);
       return node;
     });
   }
@@ -643,9 +662,8 @@ class ClosureConverter extends Transformer {
   TreeNode visitPropertyGet(PropertyGet node) {
     Name tearOffName = tearOffGetterNames[node.name];
     if (tearOffName != null) {
-      MethodInvocation replacement = new MethodInvocation(
-          node.receiver, tearOffName, new Arguments(<Expression>[]));
-      return super.visitMethodInvocation(replacement);
+      PropertyGet replacement = new PropertyGet(node.receiver, tearOffName);
+      return super.visitPropertyGet(replacement);
     }
     return super.visitPropertyGet(node);
   }
@@ -871,7 +889,7 @@ class ClosureConverter extends Transformer {
             self, procedure, contextVariable, parent.expression)));
 
         Procedure tearOffMethod = new Procedure(
-            name, ProcedureKind.Method, tearOffMethodFunction,
+            name, ProcedureKind.Getter, tearOffMethodFunction,
             fileUri: currentFileUri);
         newClassMembers.add(tearOffMethod);