Re: Cleaning up array_in()

hi.
based on Heikki v3.
I made some changes:
array_in: dim[6] all initialize with -1, lBound[6] all initialize with 1.
if ReadArrayDimensions called, then corresponding dimension lBound
will replace the initialized default 1 value.
ReadArrayStr, since array_in main function initialized dim array,
dimensions_specified true or false, I don't need to initialize again,
so I deleted that part.

to solve corner cases like  '{{1,},{1},}'::text[]. in ReadArrayStr
main switch function, like other ArrayToken, first evaluate
expect_delim then assign expect_delim.
In ATOK_LEVEL_END. if non-empty array, closing bracket either precede
with an element or another closing element. In both cases, the
previous expect_delim should be true.

in
         * FIXME: Is this still required? I believe all the checks it
performs are
         * redundant with other checks in ReadArrayDimension() and
ReadArrayStr()
         */
I deleted
-       nitems_according_to_dims = ArrayGetNItemsSafe(ndim, dim, escontext);
-       if (nitems_according_to_dims < 0)
-               PG_RETURN_NULL();
-       if (nitems != nitems_according_to_dims)
-               elog(ERROR, "mismatch nitems, %d vs %d", nitems,
nitems_according_to_dims);
but I am not sure if the following is necessary.
      if (!ArrayCheckBoundsSafe(ndim, dim, lBound, escontext))
                PG_RETURN_NULL();

I added some corner case tests like select '{{1,},{1},}'::text[];

some changes broken:
select '{{1},{}}'::text[];
-DETAIL:  Multidimensional arrays must have sub-arrays with matching dimensions.
+DETAIL:  Unexpected "," character.
I added some error checks in ATOK_LEVEL_END. The first expect_delim
part check will first generate an error, the dimension error part will
not be reached.