FULL PRODUCT VERSION :
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux 2.6.32-573.3.1.el6.x86_64

A DESCRIPTION OF THE PROBLEM :
u51 javac compiles with a warning but u60 and later javac gives an error. I see no corresponding release note about change in behavior.

REGRESSION.  Last worked in version 8u51


ERROR MESSAGES/STACK TRACES THAT OCCUR :
Ambiguity.java:14: error: reference to doSomething is ambiguous
        doSomething(Stream.of("Foo", "Bar").map(Collections::singletonList).toArray(List[]::new));
        ^
  both method doSomething(List<String>[]) in Ambiguity and method doSomething(Set<String>[]) in Ambiguity match
Note: Ambiguity.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.*;
import java.util.stream.*;

public class Ambiguity {
    public static void doSomething (List<String>[] stuff) {
        System.out.println("List Stuff");
    }

    public static void doSomething (Set<String>[] stuff) {
        System.out.println("Set Stuff");
    }

    public static void main (String[] args) {
        doSomething(Stream.of("Foo", "Bar").map(Collections::singletonList).toArray(List[]::new));
    }
}

---------- END SOURCE ----------