Changes to base(2) ghc-prim

Changes to base:
commit 240528ca9df8eb48ae4b462f65434a8de1886b1e
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Sat Mar 1 11:40:21 2014 +0100

    Tweak Haddock comments in `Data.Ord.Down` added in ebc85262c

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
    (cherry picked from commit 1dadd50d80240a03c403a07d4374b83cf9da4736)

commit a53552791a4ec99cd51060f119b64adc728ba365
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Sat Mar 1 11:29:48 2014 +0100

    Tweak documentation and update changelog.md

    This adds release note entries to changelog and tweaks Haddock comments
    with respect to the recent commits 1a9abe7a1a3c7 (re #8797) and
    f932b79948f0 (re #8745)

    Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
    (cherry picked from commit 44dec750a618a89202f80dcd695e5eb9fb74a74f)

Changes to ghc-prim:
commit a3b0a06a2bbe37122f1a3d5e20926bc30f5656d1
Author: Herbert Valerio Riedel <hvr@gnu.org>
Date:   Sat Mar 1 11:05:45 2014 +0100

    Add Since-annotation to `Coercible`

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