msvc: Select the "fast" definition of the {get,put}_be32() macros

On Intel machines, the msvc compiler defines the CPU architecture
macros _M_IX86 and _M_X64 (equivalent to __i386__ and __x86_64__
respectively). Use these macros in the pre-processor expression
to select the "fast" definition of the {get,put}_be32() macros.

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Acked-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Ramsay Jones

block-sha1/sha1.c

@@ -70,6 +70,7 @@
  */
 
 #if defined(__i386__) || defined(__x86_64__) || \
+    defined(_M_IX86) || defined(_M_X64) || \
     defined(__ppc__) || defined(__ppc64__) || \
     defined(__powerpc__) || defined(__powerpc64__) || \
     defined(__s390__) || defined(__s390x__)