javac behavior change in JDK 7 regarding private member access

This code compiles OK using javac JDK version 1.6.0_33-b03-424, but doesn't compile using javac JDK version 1.7.0_06.

public class Test {
    private final int i = 0;

    void test(Object o) {
        if (getClass().isInstance(o)) {
            System.out.println(getClass().cast(o).i);
        }
    }
}

javac output is:

Test.java:6: error: i in Test is defined in an inaccessible class or interface
        System.out.println(getClass().cast(o).i);
                                             ^
1 error

Changing the code to store the result of getClass.cast() in a temporary variable allows the program to compile without error.

This is easy to work around, but I can't find any rationale for this change in the JLS 7, or any mention of a change like this in the JDK 7 release notes. There is a mention of an access change regarding private members of type parameters to a generic, but that doesn't apply here.

Is this a regression in javac? Is it now enforcing a restriction that it wasn't enforcing before?