Pull the member context from the current target

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

Index: pkg/compiler/lib/src/ssa/builder.dart
diff --git a/pkg/compiler/lib/src/ssa/builder.dart b/pkg/compiler/lib/src/ssa/builder.dart
index 1943e06c96f520ac9b7fefaea911f96d6a0a2ee3..b038a0dd6a8e9478e84a6734a1c2016120ce82e4 100644
--- a/pkg/compiler/lib/src/ssa/builder.dart
+++ b/pkg/compiler/lib/src/ssa/builder.dart
@@ -5517,7 +5517,7 @@ class SsaBuilder extends ast.Visitor
     //     }
     ExecutableElement loopVariable = elements.getForInVariable(node);
     SyntheticLocal indexVariable =
-        new SyntheticLocal('_i', loopVariable, loopVariable.memberContext);
+        new SyntheticLocal('_i', loopVariable, target);
     TypeMask boolType = commonMasks.boolType;
 
     // These variables are shared by initializer, condition, body and update.