Recent imm changes triggered widespread valgrind errors?

[Dan Kegel]

Aric, can you have a look?

Any call to CreateWindow now spews lots of Valgrind errors.
For instance,
http://kegel.com/wine/valgrind/logs-2008-04-01/vg-advpack_install-diff.txt
contains:
+ Conditional jump or move depends on uninitialised value(s)
+    at  RtlInitUnicodeString (unicode.h:212)
+    by  LoadLibraryExW (module.c:924)
+    by  LoadLibraryW (module.c:968)
+    by  ImmCreateContext (imm.c:143)
+    by  X11DRV_SetupXIM (xim.c:510)
+    by  x11drv_init_thread_data (x11drv_main.c:654)
+    by  X11DRV_SetWindowPos (x11drv.h:517)
+    by  set_window_pos (winpos.c:1919)
+    by  WIN_CreateWindowEx (win.c:1121)
+    by  CreateWindowExW (win.c:1351)
+    by  manage_desktop (desktop.c:224)
+    by  WinMain (explorer.c:136)
+    by  main (exe_main.c:48)