Define _AMD64_, MP_CHAR_STORE_SLOW, and MP_IS_LITTLE_ENDIAN

Define _AMD64_, MP_CHAR_STORE_SLOW, and MP_IS_LITTLE_ENDIAN
for 64-bit Windows builds.

This matches the upstream NSS build system.

R=jschuh@chromium.org,rsleevi@chromium.org
BUG=167951
TEST=none

[wtc, 2013-02-12 04:34:43]

The upstream NSS build system defines these macros at

http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/security/coreconf/WIN32.m...

http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/security/nss/lib/freebl/M...

See also Linux x86-64, which defines the last two macros:
http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/security/nss/lib/freebl/M...

[Ryan Sleevi, 2013-02-12 18:20:39]

LGTM.

Note: These are also addressed in
https://codereview.chromium.org/11738002/diff/2002/nss.gyp , although I haven't
landed that per the YASM discussion with bsmith@ and wanting to investigate
using YASM on the NSS GAS files, rather than converting to MASM.

[jschuh, 2013-02-12 18:22:12]

lgtm

[commit-bot: I haz the power, 2013-02-14 23:45:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wtc@chromium.org/12210134/1

[commit-bot: I haz the power, 2013-02-14 23:45:37]

Change committed as 182578

[wtc, 2013-02-14 23:49:17]

On 2013/02/12 18:20:39, Ryan Sleevi wrote:
>
> Note: These are also addressed in
> https://codereview.chromium.org/11738002/diff/2002/nss.gyp ,

Thanks. I knew I suggested these changes to you when I reviewed
that CL.

I was in this code again recently when I added the ARM assembly
code to iOS and needed to study these freebl configuration macros,
so I wrote this CL in that process.