Strangeness in ASRT

[Richard Stallman]

This seems to have a bug which breaks compilation.

    /* The IDX==IDX tries to detect when the macro argument is side-effecting.  
*/
    #define ASET(ARRAY, IDX, VAL)       \
      (eassert ((IDX) == (IDX)),                                \
       eassert ((IDX) >= 0 && (IDX) < ASIZE (ARRAY)),   \
       ASLOT ((ARRAY), (IDX)) = (VAL))

Changing ASLOT to AREF makes it compile.  (Bootstrapping still crashes
as before.)

What is the purpose of these tests?  The expansion of AREF
substitutes IDX only once, so there is no problem if it has
a side effect.