Tests: Only disable crashhandler on UNIX

On Windows disabling the crashhandler results in re-enabling the
Windows internal error reporting which causes trouble as well, so
limit disabling of crashhandler to Linux/OSX.

This patch more or less amends 80352d703c.

Change-Id: I0588cd22c2ff894e07378524baf03794963c92a1
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/libs/extensionsystem/pluginmanager.cpp

@@ -51,6 +51,7 @@
 #include <utils/qtcassert.h>
 
 #ifdef WITH_TESTS
+#include <utils/hostosinfo.h>
 #include <QTest>
 #endif
 
@@ -1025,7 +1026,8 @@ static int executeTestPlan(const TestPlan &testPlan)
                 << QLatin1String("-maxwarnings") << QLatin1String("0"); // unlimit output
         qExecArguments << functions;
         // avoid being stuck in QTBUG-24925
-        qExecArguments << "-nocrashhandler";
+        if (!Utils::HostOsInfo::isWindowsHost())
+            qExecArguments << "-nocrashhandler";
         failedTests += QTest::qExec(testObject, qExecArguments);
     }