Merge some more changes from ActivePerl 5.8.8.816

Merge some more changes from ActivePerl 5.8.8.816

See (again):
http://downloads.activestate.com/ActivePerl/src/5.8/AP816_diff.txt

These changes improve support for the MS 64-bit compiler in
win32/Makefile (and tentatively make the same changes to
win32/makefile.mk), and also switches the now deprecated -Gf switch to
-GF for all flavours of VC++ instead of just the latest ones.

(See:
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-02/msg00353.html
for a comment on the s/-Gf/-GF/ change.)

p4raw-id: //depot/perl@27556