Find the language-specific data address in all cases

The spec seems to say the data will come after the personality function inside
the exception handler table:

"""
Conceptually, an exception-handling table entry begins with the address of the personality routine:
/* See §7.2 for details of the various _Unwind types */
typedef _Unwind_Reason_Code (*PersonalityRoutine)(_Unwind_State, _Unwind_Control_Block *, _Unwind_Context *);
struct _Unwind_EHT_Entry {
  PersonalityRoutine pr;
  /* then other data understood only by the personality routine */
};
"""

Change-Id: I2f8f32e39159f030c2b98ae7a8757ad216eeff18