Lookup getClosureScope by member instead of node

pkg/compiler/lib/src/ssa/builder_kernel.dart

Index: pkg/compiler/lib/src/ssa/builder_kernel.dart
diff --git a/pkg/compiler/lib/src/ssa/builder_kernel.dart b/pkg/compiler/lib/src/ssa/builder_kernel.dart
index b9090525c09aa8dd1cd64040114562e23ab53625..b2d206e4701cc92693e910865b0d61cd2e2d185b 100644
--- a/pkg/compiler/lib/src/ssa/builder_kernel.dart
+++ b/pkg/compiler/lib/src/ssa/builder_kernel.dart
@@ -349,8 +349,8 @@ class KernelSsaGraphBuilder extends ir.Visitor
 
       // If there are locals that escape (i.e. mutated in closures), we pass the
       // box to the constructor.
-      ClosureScope scopeData = closureDataLookup
-          .getClosureScope(constructorElement.resolvedAst.node);
+      ClosureScope scopeData =
+          closureDataLookup.getClosureScope(constructorElement);
       if (scopeData.requiresContextBox) {
         bodyCallInputs.add(localsHandler.readLocal(scopeData.context));
       }
@@ -613,8 +613,7 @@ class KernelSsaGraphBuilder extends ir.Visitor
       ResolvedAst resolvedAst = astElement.resolvedAst;
       localsHandler.scopeInfo = newScopeInfo;
       if (resolvedAst.kind == ResolvedAstKind.PARSED) {
-        localsHandler.enterScope(
-            closureDataLookup.getClosureScope(resolvedAst.node),
+        localsHandler.enterScope(closureDataLookup.getClosureScope(astElement),
             forGenerativeConstructorBody:
                 astElement.isGenerativeConstructorBody);
       }
@@ -706,7 +705,7 @@ class KernelSsaGraphBuilder extends ir.Visitor
     localsHandler.startFunction(
         targetElement,
         closureDataLookup.getScopeInfo(targetElement),
-        closureDataLookup.getClosureScope(functionNode),
+        closureDataLookup.getClosureScope(targetElement),
         parameterMap,
         isGenerativeConstructorBody: _targetIsConstructorBody);
     close(new HGoto()).addSuccessor(block);