user32/tests: Test for behavior of WM_SETTEXT handler

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
http://testbot.winehq.org/JobDetails.pl?Key=8838

Your paranoid android.


=== WNT4WSSP6 (32 bit msg) ===
msg.c:5649: Test failed: WM_SETTEXT on a button: 3: the msg 0x0138 was expected, but got msg 0x8000 instead

=== W7PROX64 (64 bit msg) ===
Timeout