PR# 13777 Some uses of constant 0x7FFFFFFF are wrong for 64-bit Eiffel

Some of the uses of constant 0x7FFFFFFF, intended to represent the maximum
integer or long integer, are incorrect for 64-bit Eiffel.  For example,
in garcol.c we have:

                        if (plsc_per < 0) {
                                        /* Overflow here, so restore back the m\ax positive integer value */
                                plsc_per = 0x7FFFFFFF;

Since the type of `plsc_per' is long, this is not the maximum long integer.

Similarly this is wrong (also in garcol.c):

              EIF_INTEGER max_size = 0, min_size = 0x7fffffff;

You should do a case-independent search for "0x7fffffff" (there are only 22
occurences) and review them to see which are incorrect.

I suggest #include <values.h> somewhere to make MAXINT and MAXLONG available
and use them instead of constants, assuming this is ANSI standard.  You can
add your own defines if necessary.