The following program:

class A<T> {
  Exception[] bar(A<? super Exception[]> x, A<? super Throwable[]> y){
    return foo(x, y);
  }

  <T> T foo(A<? super T> x, A<? super T> y){
    return null;
  }
}

Crashes with SOE:

The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
        at com.sun.tools.javac.code.Type.hasTag(Type.java:133)
        at com.sun.tools.javac.code.Types$12.visitClassType(Types.java:1928)
        at com.sun.tools.javac.code.Types$12.visitClassType(Types.java:1916)
        at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:999)
        at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4519)
        at com.sun.tools.javac.code.Types.asSuper(Types.java:1913)
        at com.sun.tools.javac.code.Types$4.visitClassType(Types.java:919)
        at com.sun.tools.javac.code.Types$4.visitClassType(Types.java:840)
        at com.sun.tools.javac.code.Type$ClassType.accept(Type.java:999)
        at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4519)
        at com.sun.tools.javac.code.Types.isSubtype(Types.java:836)
        at com.sun.tools.javac.code.Types.isSubtypeNoCapture(Types.java:810)
        at com.sun.tools.javac.code.Types$4.visitType(Types.java:854)
        at com.sun.tools.javac.code.Types$4.visitType(Types.java:840)
        at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visitTypeVar(Types.java:4525)
        at com.sun.tools.javac.code.Types$SimpleVisitor.visitCapturedType(Types.java:4570)
        at com.sun.tools.javac.code.Type$CapturedType.accept(Type.java:1696)
        at com.sun.tools.javac.code.Types$DefaultTypeVisitor.visit(Types.java:4519)
        at com.sun.tools.javac.code.Types.isSubtype(Types.java:836)
        at com.sun.tools.javac.code.Types.isSubtypeNoCapture(Types.java:810)
        at com.sun.tools.javac.code.Types.closureMin(Types.java:3561)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3752)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
        at com.sun.tools.javac.code.Types.glbFlattened(Types.java:3773)
...