Fix compilation warnings on MS-Windows

* src/w32.c (_ANONYMOUS_UNION, _ANONYMOUS_STRUCT): Remove
definitions of these macros, which seem to be unneeded and cause
compiler warnings.
* src/fileio.c (NOMINMAX): Avoid compiler warnings about unused
macros.
* src/firstfile.c (dummy_main_reference): Rename from 'dummy' and
make it external, to avoid compiler warning.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/firstfile.c b/src/firstfile.c
index 188d4f81b5c..962d6f6c7f6 100644
--- a/src/firstfile.c
+++ b/src/firstfile.c
@@ -26,7 +26,7 @@ char my_begbss[1];  /* Do not initialize this variable.  */
 static char _my_begbss[1];
 char * my_begbss_static = _my_begbss;
 
-/* Add a dummy reference to ensure emacs.obj is linked in.  */
+/* Add a dummy reference to ensure emacs.o is linked in.  */
 extern int main (int, char **);
-static int (*dummy) (int, char **) = main;
+int (*dummy_main_reference) (int, char **) = main;
 #endif