[jdk12] adding support for the new nodes introduced for the improvements to switch statements, and the ‘switch expression’ preview feature, as well as support for the concept of preview features in general.

test/pretty/resource/before/Switch11.java

@@ -0,0 +1,12 @@
+// version :11
+public class Switch11 {
+	public void basic() {
+		switch (5) {
+		case 1:
+		case 2:
+			System.out.println("OK");
+			break;
+		default:
+		}
+	}
+}