javac treats final parameters as non-blank finals, performing DA/DU
analysis on them. Some other compilers don't. The jacks test 16.1.5-not-assignable-5 checks for this. Which is right?

The following test distinguishes the compiler behavior.

class T {
public static void main(final String[] args) {
    if (true ? true : (args = null));
}
}

similarly, the exception parameter declaration in a catch block.