Changes to integer-gmp(2)

Changes to integer-gmp:
commit 0476327376045838375fbbe4a78c02859a1913cb
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Thu Jan 16 22:56:37 2014 +0100

    Dont use big/small-int primops on IL32P64 (i.e. Win/x86_64) for now

    This is due to `mpz_*()` functions having @long@ arguments which are
    32bit on IL32P64, whereas `Int#` and `Word#` are 64bit wide, causing all
    sorts of malfunction due to truncation.

    This affects mostly the new big/small-int primops introduced in the
    course of #8647, so when `SIZEOF_W != SIZEOF_LONG` we simply fall back
    to using the big/big-int primops. big/small primops implemented via the
    low-level `mpn_*()` GMP operations are not affected, as those use
    `mp_limb_t` arguments.

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

commit dbb7e640d2856046dd82f134aa3eb6986472f698
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Thu Jan 16 21:39:06 2014 +0100

    Introduce new SIZEOF_MP_LIMB_T derived constant

    This allows to simplify code in `float.c` and to encode the
    "sizeof(mp_limb_t) != sizeof(W_)" assumption as a compile-time
    assertion.

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>