pgsql: Remove all the special-case code for INT64_IS_BUSTED, per

Log Message:
-----------
Remove all the special-case code for INT64_IS_BUSTED, per decision that
we're not going to support that anymore.

I did keep the 64-bit-CRC-with-32-bit-arithmetic code, since it has a
performance excuse to live.  It's a bit moot since that's all ifdef'd
out, of course.

Modified Files:
--------------
    pgsql/contrib/btree_gin:
        btree_gin.c (r1.3 -> r1.4)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/btree_gin/btree_gin.c?r1=1.3&r2=1.4)
    pgsql/src/backend/access/hash:
        hashfunc.c (r1.61 -> r1.62)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hashfunc.c?r1=1.61&r2=1.62)
    pgsql/src/backend/libpq:
        pqformat.c (r1.51 -> r1.52)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/libpq/pqformat.c?r1=1.51&r2=1.52)
    pgsql/src/backend/utils/adt:
        int8.c (r1.76 -> r1.77)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/int8.c?r1=1.76&r2=1.77)
        numeric.c (r1.120 -> r1.121)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/numeric.c?r1=1.120&r2=1.121)
        txid.c (r1.10 -> r1.11)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/txid.c?r1=1.10&r2=1.11)
        varbit.c (r1.60 -> r1.61)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/varbit.c?r1=1.60&r2=1.61)
    pgsql/src/backend/utils/fmgr:
        fmgr.c (r1.128 -> r1.129)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c?r1=1.128&r2=1.129)
    pgsql/src/backend/utils/hash:
        pg_crc.c (r1.22 -> r1.23)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/hash/pg_crc.c?r1=1.22&r2=1.23)
    pgsql/src/backend/utils/misc:
        guc.c (r1.531 -> r1.532)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c?r1=1.531&r2=1.532)
    pgsql/src/bin/pg_dump:
        pg_backup_tar.c (r1.66 -> r1.67)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_backup_tar.c?r1=1.66&r2=1.67)
    pgsql/src/include:
        c.h (r1.238 -> r1.239)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/c.h?r1=1.238&r2=1.239)
        pg_config_manual.h (r1.39 -> r1.40)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config_manual.h?r1=1.39&r2=1.40)
    pgsql/src/include/commands:
        sequence.h (r1.43 -> r1.44)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/sequence.h?r1=1.43&r2=1.44)
    pgsql/src/include/utils:
        pg_crc.h (r1.22 -> r1.23)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/pg_crc.h?r1=1.22&r2=1.23)
    pgsql/src/interfaces/ecpg/include:
        pgtypes_interval.h (r1.14 -> r1.15)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/include/pgtypes_interval.h?r1=1.14&r2=1.15)