tst_QEventDispatcher autotest fails on macOS 10.13

agent:2018/11/12 10:46:51 build.go:653: 
 agent:2018/11/12 10:46:51 build.go:448: Executing instruction 433 of 982 - RunQtUnitTest
 agent:2018/11/12 10:46:51 build.go:313: [make check -j1] 900 900
 agent:2018/11/12 10:46:51 build.go:193: /Users/qt/work/qt/qtbase/tests/auto/gui/kernel/qguieventdispatcher/target_wrapper.sh  ./tst_qguieventdispatcher -o /Users/qt/work/testresults/tests/auto/gui/kernel/qguieventdispatcher749442026,xml -o -,txt
 agent:2018/11/12 10:46:51 build.go:193: ********* Start testing of tst_QEventDispatcher *********
 agent:2018/11/12 10:46:51 build.go:193: Config: Using QtTest library 5.12.0, Qt 5.12.0 (x86_64-little_endian-lp64 shared (dynamic) release build; by Clang 10.0.0 (clang-1000.11.45.2) (Apple))
 agent:2018/11/12 10:46:51 build.go:193: PASS   : tst_QEventDispatcher::initTestCase()
 agent:2018/11/12 10:46:51 build.go:193: FAIL!  : tst_QEventDispatcher::registerTimer() QTestLib: This test case check ("(((receivedEventType) == (int(QEvent::Timer))))") failed because the requested timeout (20 ms) was too short, 20 ms would have been sufficient this time.
 agent:2018/11/12 10:46:51 build.go:193:    Loc: [../../../corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp(139)]
 agent:2018/11/12 10:46:51 build.go:193: FAIL!  : tst_QEventDispatcher::sendPostedEvents(WaitForMoreEvents) Compared values are not the same
 agent:2018/11/12 10:46:51 build.go:193:    Actual   (receivedEventType): 1
 agent:2018/11/12 10:46:51 build.go:193:    Expected (int(QEvent::User)): 1000
 agent:2018/11/12 10:46:51 build.go:193:    Loc: [../../../corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp(194)]
 agent:2018/11/12 10:46:51 build.go:193: FAIL!  : tst_QEventDispatcher::sendPostedEvents(AllEvents) Compared values are not the same
 agent:2018/11/12 10:46:51 build.go:193:    Actual   (receivedEventType): 1
 agent:2018/11/12 10:46:51 build.go:193:    Expected (int(QEvent::User)): 1000
 agent:2018/11/12 10:46:51 build.go:193:    Loc: [../../../corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp(194)]
 agent:2018/11/12 10:46:51 build.go:193: PASS   : tst_QEventDispatcher::processEventsOnlySendsQueuedEvents()
 agent:2018/11/12 10:46:51 build.go:193: PASS   : tst_QEventDispatcher::cleanupTestCase()
 agent:2018/11/12 10:46:51 build.go:193: Totals: 3 passed, 3 failed, 0 skipped, 0 blacklisted, 188ms