Temporarily skip tst_qtcuncurrentrun::pollForIsFinished in emulator

This test causes instability in the CI, but so far nobody could
reproduce it outside of that specific CI environment. Skip it for now,
and investigate the root cause later.

Task-number: QTBUG-106906
Change-Id: Idbbc560236ac475fcb4fdd5980397393f7a95474
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit fbf55619daea26dadb600100e87da48eef3dc714)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/concurrent/qtconcurrentrun/CMakeLists.txt

@@ -9,6 +9,7 @@ qt_internal_add_test(tst_qtconcurrentrun
         tst_qtconcurrentrun.cpp
     PUBLIC_LIBRARIES
         Qt::Concurrent
+        Qt::TestPrivate
 )
 
 ## Scopes:

tests/auto/concurrent/qtconcurrentrun/tst_qtconcurrentrun.cpp

@@ -10,6 +10,8 @@
 #include <QTimer>
 #include <QFutureSynchronizer>
 
+#include <QtTest/private/qemulationdetector_p.h>
+
 using namespace QtConcurrent;
 
 class tst_QtConcurrentRun: public QObject
@@ -699,6 +701,9 @@ static void runFunction()
 
 void tst_QtConcurrentRun::pollForIsFinished()
 {
+    // proxy check for QEMU; catches slightyl more though
+    if (QTestPrivate::isRunningArmOnX86())
+        QSKIP("Runs into spurious crashes on QEMU -- QTBUG-106906");
     const int numThreads = std::max(4, 2 * QThread::idealThreadCount());
     QThreadPool::globalInstance()->setMaxThreadCount(numThreads);