Workaround FTBFS when building with gcc 6 on i686
    
    For reference, here's what Valgrind reports when running qmake:
    
    ==9360== Process terminating with default action of signal 11 (SIGSEGV)
    ==9360==  Access not within mapped region at address 0xC
    ==9360==    at 0x805BD18: data (qarraydata.h:55)
    ==9360==    by 0x805BD18: data (qarraydata.h:199)
    ==9360==    by 0x805BD18: constData (qbytearray.h:483)
    ==9360==    by 0x805BD18: fromLocal8Bit (qstring.h:541)
    ==9360==    by 0x805BD18: QMakeGlobals::getEnv(QString const&) const (qmakeglobals.cpp:283)
    ==9360==    by 0x805CF6B: QMakeGlobals::getPathListEnv(QString const&) const (qmakeglobals.cpp:289)
    ==9360==    by 0x806731C: QMakeEvaluator::updateMkspecPaths() (qmakeevaluator.cpp:1441)
    ==9360==    by 0x80720DF: QMakeEvaluator::loadSpec() (qmakeevaluator.cpp:1202)
    ==9360==    by 0x8070DF3: QMakeEvaluator::visitProFile(ProFile*, QMakeHandler::EvalFileType, QFlags<QMakeEvaluator::LoadFlag>) (qmakeevaluator.cpp:1357)
    ==9360==    by 0x8071028: QMakeEvaluator::evaluateFile(QString const&, QMakeHandler::EvalFileType, QFlags<QMakeEvaluator::LoadFlag>) (qmakeevaluator.cpp:1843)
    ==9360==    by 0x804A4D3: QMakeProject::read(QString const&, QFlags<QMakeEvaluator::LoadFlag>) (project.cpp:74)
    ==9360==    by 0x8056F49: runQMake(int, char**) (main.cpp:372)
    ==9360==    by 0x8049F6A: main (main.cpp:408)