Fix build failures on Windows and Mac.

server-tools/instance-manager/WindowsService.cpp:
  Include my_global.h for DBUG_ASSERT.
server-tools/instance-manager/mysqlmanager.cc:
  Include my_dir.h for umask().

server-tools/instance-manager/WindowsService.cpp

@@ -15,6 +15,7 @@
 
 #include <windows.h>
 
+#include "my_global.h"
 #include "WindowsService.h"
 
 static WindowsService *gService;

server-tools/instance-manager/mysqlmanager.cc

@@ -14,6 +14,7 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
 #include <my_global.h>
+#include <my_dir.h>
 #include <my_sys.h>
 
 #include <string.h>