For all DLLs with defined DllMain and which do not require
DLL_THREAD_ATTACH/DLL_THREAD_DETACH notifications, call
DisableThreadLibraryCalls() in order to slightly improve performance
on thread creation/exiting.

diff --git a/dlls/snmpapi/main.c b/dlls/snmpapi/main.c
index cc8c1fe..bf20c2d 100644
--- a/dlls/snmpapi/main.c
+++ b/dlls/snmpapi/main.c
@@ -20,8 +20,7 @@
 
 #include "config.h"
 
-#include "windef.h"
-
+#include "winbase.h"
 #include "wine/debug.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(snmpapi);
@@ -38,13 +37,10 @@
 
     switch(fdwReason) {
     case DLL_PROCESS_ATTACH:
+        DisableThreadLibraryCalls(hInstDLL);
         break;
     case DLL_PROCESS_DETACH:
         break;
-    case DLL_THREAD_ATTACH:
-        break;
-    case DLL_THREAD_DETACH:
-        break;
     }
 
     return TRUE;