shift setParent up one level

runtime/Java/src/org/antlr/v4/runtime/RuleContext.java

@@ -163,6 +163,12 @@ public class RuleContext implements RuleNode {
 	 */
 	public void setAltNumber(int altNumber) { }
 
+	/** @since 4.7. {@see ParseTree#setParent} comment */
+	@Override
+	public void setParent(RuleContext parent) {
+		this.parent = parent;
+	}
+
 	@Override
 	public ParseTree getChild(int i) {
 		return null;

runtime/Java/src/org/antlr/v4/runtime/tree/ParseTree.java

@@ -24,6 +24,24 @@ public interface ParseTree extends SyntaxTree {
 	@Override
 	ParseTree getChild(int i);
 
+
+	/** Set the parent for this node.
+	 *
+	 *  This is not backward compatible as it changes
+	 *  the interface but no one was able to create custom
+	 *  nodes anyway so I'm adding as it improves internal
+	 *  code quality.
+	 *
+	 *  One could argue for a restructuring of
+	 *  the class/interface hierarchy so that
+	 *  setParent, addChild are moved up to Tree
+	 *  but that's a major change. So I'll do the
+	 *  minimal change, which is to add this method.
+	 *
+	 *  @since 4.7
+	 */
+	void setParent(RuleContext parent);
+
 	/** The {@link ParseTreeVisitor} needs a double dispatch method. */
 	<T> T accept(ParseTreeVisitor<? extends T> visitor);
 

runtime/Java/src/org/antlr/v4/runtime/tree/TerminalNode.java

@@ -11,15 +11,4 @@ import org.antlr.v4.runtime.Token;
 
 public interface TerminalNode extends ParseTree {
 	Token getSymbol();
-
-	/** Set the parent for this leaf node.
-	 *
-	 *  Technically, this is not backward compatible as it changes
-	 *  the interface but no one was able to create custom
-	 *  TerminalNodes anyway so I'm adding as it improves internal
-	 *  code quality.
-	 *
-	 *  @since 4.7
-	 */
-	void setParent(RuleContext parent);
 }