Fix style and copyrights.

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/frame/DestructuringAssignmentNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2019, Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates.
  * Copyright (c) 2013, Regents of the University of California
  *
  * All rights reserved.
@@ -35,7 +35,6 @@
 import com.oracle.graal.python.nodes.PRaiseNode;
 import com.oracle.graal.python.nodes.builtins.TupleNodes;
 import com.oracle.graal.python.nodes.expression.ExpressionNode;
-import com.oracle.graal.python.nodes.frame.DestructuringAssignmentNodeGen.WriteSequenceStorageStarredNodeGen;
 import com.oracle.graal.python.nodes.object.IsBuiltinClassProfile;
 import com.oracle.graal.python.nodes.statement.StatementNode;
 import com.oracle.graal.python.runtime.PythonContext;