NPE in escjava.translate.TrAnExpr.trSpecExprI

The following code causes an NPE. The code calls a
helper method then throws a non-default exception in a
constructor.

class C
{
C() throws Exception {
helperMethod();
throw new Exception("E");
}

private /*@ helper @*/ void helperMethod() {
return;
}
}

Removing the helper annotation, or throwing using the
default constructor for Exception both cause the NPE to
disappear.