Skip constantly failing v8 test on Windows

tst_qscriptv8testsuite::smi-negative-zero() fails constantly on
Windows 8. QTBUG-41321

Change-Id: I53538f281f725b215fcf6c2f485953341f938946
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>

tests/auto/qscriptv8testsuite/skip.txt

@@ -29,6 +29,7 @@ to-precision | Unresolved failures on Mac OS X (Cocoa)
 
 [Q_OS_WIN]
 to-precision | Unresolved failures on Windows
+smi-negative-zero | Unresolved failure on Windows 8 (QTBUG-41321)
 
 [Q_OS_LINUX]
 smi-negative-zero | Unresolved sign failure for Ubuntu 11.10 x64 (QTBUG-23463)