tst_largefile is broken on 64-bit Linux

********* Start testing of tst_LargeFile *********
Config: Using QTest library 5.0.0, Qt 5.0.0
PASS   : tst_LargeFile::initTestCase()
PASS   : tst_LargeFile::createSparseFile()
PASS   : tst_LargeFile::fillFileSparsely()
PASS   : tst_LargeFile::closeSparseFile()
PASS   : tst_LargeFile::fileCreated()
PASS   : tst_LargeFile::filePositioning()
PASS   : tst_LargeFile::fdPositioning()
PASS   : tst_LargeFile::streamPositioning()
PASS   : tst_LargeFile::openFileForReading()
PASS   : tst_LargeFile::readFile()
PASS   : tst_LargeFile::mapFile()
QWARN  : tst_LargeFile::mapOffsetOverflow() QFSFileEngine::map: Mapping a file beyond its size is not portable
FAIL!  : tst_LargeFile::mapOffsetOverflow() '!address' returned FALSE. ()
   Loc: [tst_largefile.cpp(529)]
PASS   : tst_LargeFile::closeFile()
PASS   : tst_LargeFile::cleanupTestCase()
Totals: 13 passed, 1 failed, 0 skipped
********* Finished testing of tst_LargeFile *********