[test] work in progress: Make test.javac6 pass all tests.

The `test.javac6` job causes a ton of errors because many tests use java8+ features. Marking them off as java8+ targeted only.

test/transform/resource/before/ValDelegateMethodReference.java

@@ -1,3 +1,4 @@
+//version 8:
 //platform !eclipse: Requires a 'full' eclipse with intialized workspace, and we don't (yet) have that set up properly in the test run.
 import lombok.Getter;
 import lombok.Setter;