[autotest] tst_qscriptjstestsuite always fails on windows 64 bit

This test is always failing on win64-msvc2012_developer-build_qtnamespace_Windows_8 stage
Testing tst_QScriptJsTestSuite
FAIL! : tst_QScriptJsTestSuite::ecma/Expressions(-(-2147483648) == 2147483648) Compared values are not the same
Actual (actual): -2147483648
Expected (expect): 2147483648
ecma/Expressions/11.4.7-02.js(317) : failure location
FAIL! : tst_QScriptJsTestSuite::ecma/TypeConversion(- -"0x80000000") Compared values are not the same
Actual (actual): -2147483648
Expected (expect): 2147483648
ecma/TypeConversion/9.3.1-3.js(93) : failure location
FAIL! : tst_QScriptJsTestSuite::ecma/TypeConversion(- -"0x80000000") Compared values are not the same
Actual (actual): -2147483648
Expected (expect): 2147483648
ecma/TypeConversion/9.3.1-3.js(687) : failure location
Totals: 29935 passed, 3 failed, 147 skipped

See for example http://testresults.qt-project.org/ci/Qt5_stable_Integration/build_00407/win64-msvc2012_developer-build_qtnamespace_Windows_8/log.txt.gz