implicit use of this before super() should be disallowed

javac fails to compile the following program, even though it violates
no rules in the spec. I suspect his should be disallowed by the
specification, as the constructor of Up could call a member method of Fake
and observe the state of Fake before Fake's superclass constructor has been
called. If we intend this to be illegal, the spec needs to clearly
disallow it.



frog:~/workspaces/test/4626788 $ cat -n T.java
     1 class Top {
     2 Top(Object o) {}
     3 }
     4
     5 class Bottom {
     6 int x = 2;
     7
     8 class Fake extends Top {
     9 class Up {
    10 Up() { int y = x; }
    11 }
    12
    13 Fake() {
    14 super(new Up() {});
    15 }
    16 }
    17 }
frog:~/workspaces/test/4626788 $ newjavac -target 1.4 T.java
T.java:14: no enclosing instance of type Bottom.Fake is in scope
            super(new Up() {});
                           ^
1 error
frog:~/workspaces/test/4626788 $ cat -n U.java
     1 class Top {
     2 Top(Object o) {}
     3 }
     4
     5 class Bottom {
     6 int x = 2;
     7
     8 class Fake extends Top {
     9 class Up {
    10 Up() { int y = x; }
    11 }
    12
    13 Fake() {
    14 super(new Up());
    15 }
    16 }
    17 }
frog:~/workspaces/test/4626788 $ newjavac -target 1.4 U.java
U.java:14: cannot reference this before supertype constructor has been called
            super(new Up());
                  ^
1 error
frog:~/workspaces/test/4626788 $