[1/3] user32/tests: Add some tests for mdiclient scrolling.

[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
https://testbot.winehq.org/JobDetails.pl?Key=18379

Your paranoid android.


=== w8 (32 bit win) ===
win.c:3605: Test failed: hwnd 000201D2 message 0118

=== w1064 (32 bit win) ===
win.c:6846: Test failed: 0x80/0x1c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6868: Test failed: 0x80/0x1010000: window rect 0,0-1024,768
win.c:6846: Test failed: 0x80/0x81c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6846: Test failed: 0/0x41c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6846: Test failed: 0x40000/0x41c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6846: Test failed: 0x80/0x41c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6846: Test failed: 0x80/0x1c50000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6868: Test failed: 0x80/0x1050000: window rect 0,0-1024,768
win.c:6846: Test failed: 0x80/0x1c10000: window rect 0,0-1024,768 must be in 0,0-1024,728
win.c:6868: Test failed: 0x80/0x1410000: window rect 0,0-1024,768

=== w864 (64 bit win) ===
win.c:3605: Test failed: hwnd 000000000002019A message 0118