xmlconfig: Use program_invocation_short_name when building for cygwin

mesa/mesa/src/mesa/drivers/dri/common/xmlconfig.c:104:10: warning: #warning "Per application configuration won't work with your OS version." [-Wcpp]
 #        warning "Per application configuration won't work with your OS version."

Signed-off-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>
Reviewed-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/drivers/dri/common/xmlconfig.c

@@ -45,6 +45,8 @@
 extern char *program_invocation_name, *program_invocation_short_name;
 #    endif
 #    define GET_PROGRAM_NAME() program_invocation_short_name
+#elif defined(__CYGWIN__)
+#    define GET_PROGRAM_NAME() program_invocation_short_name
 #elif defined(__FreeBSD__) && (__FreeBSD__ >= 2)
 #    include <osreldate.h>
 #    if (__FreeBSD_version >= 440000)