diff -r f36d08a3e700 -r 7bf4f1b5e438 src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java	Wed Jun 13 10:34:51 2018 +0200
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java	Wed Jun 13 12:52:21 2018 +0200
@@ -181,7 +181,8 @@
         DIAMOND_WITH_ANONYMOUS_CLASS_CREATION(JDK9, Fragments.FeatureDiamondAndAnonClass, DiagKind.NORMAL),
         UNDERSCORE_IDENTIFIER(MIN, JDK8),
         PRIVATE_INTERFACE_METHODS(JDK9, Fragments.FeaturePrivateIntfMethods, DiagKind.PLURAL),
-        LOCAL_VARIABLE_TYPE_INFERENCE(JDK10);
+        LOCAL_VARIABLE_TYPE_INFERENCE(JDK10),
+        IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES(JDK1_2, JDK8);
 
         enum DiagKind {
             NORMAL,