user32: Reimplement UserYield using PeekMessageW.

dlls/user32/message.c

@@ -3364,28 +3364,6 @@ DWORD WINAPI WaitForInputIdle( HANDLE hProcess, DWORD dwTimeOut )
 }
 
 
-/***********************************************************************
- *		UserYield (USER.332)
- */
-void WINAPI UserYield16(void)
-{
-   DWORD count;
-
-    /* Handle sent messages */
-    process_sent_messages();
-
-    /* Yield */
-    ReleaseThunkLock(&count);
-
-    if (count)
-    {
-        RestoreThunkLock(count);
-        /* Handle sent messages again */
-        process_sent_messages();
-    }
-}
-
-
 /***********************************************************************
  *		RegisterWindowMessageA (USER32.@)
  *		RegisterWindowMessage (USER.118)

dlls/user32/msg16.c

@@ -505,6 +505,16 @@ BOOL16 WINAPI SetMessageQueue16( INT16 size )
 }
 
 
+/***********************************************************************
+ *		UserYield (USER.332)
+ */
+void WINAPI UserYield16(void)
+{
+    MSG msg;
+    PeekMessageW( &msg, 0, 0, 0, PM_REMOVE | PM_QS_SENDMESSAGE );
+}
+
+
 /***********************************************************************
  *		GetQueueStatus (USER.334)
  */

dlls/user32/user32.spec

@@ -784,7 +784,6 @@
 @ stdcall GetDriverModuleHandle16(long)
 @ stdcall OpenDriver16(str str long)
 @ stdcall SendDriverMessage16(long long long long)
-@ stdcall UserYield16()
 
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 # Wine dll separation hacks, these will go away, don't use them