8005299: Add FunctionalInterface checking to javac
Summary: Javac should check that types annotated with @FunctionalInterface are indeed functional interfaces
Reviewed-by: jjg
NonSAM2.java:13:1: compiler.err.types.incompatible.diff.ret: Bar1, Foo1, getAge(java.lang.String)
NonSAM2.java:15:1: compiler.err.name.clash.same.erasure.no.override: getOldest(java.util.List<?>), C, getOldest(java.util.List<java.lang.Number>), A
NonSAM2.java:16:1: compiler.err.name.clash.same.erasure.no.override: getOldest(java.util.List<?>), C, getOldest(java.util.List<java.lang.Number>), A
NonSAM2.java:17:1: compiler.err.name.clash.same.erasure.no.override: getOldest(java.util.List<java.lang.Integer>), D, getOldest(java.util.List<java.lang.Number>), A
NonSAM2.java:21:1: compiler.err.name.clash.same.erasure.no.override: m(S), Bar2, m(T), Foo2
5 errors