Multiple crashes on QtXmlPatterns autotests in static developer build

Platform VxWorks 7 SR650 clang imx6 sabrelite.

Following testcases crashs with similar symptons:

• checkxmlfiles
• patternistexamples
• qabstractxmlnodemodel
• qabstractxmlreceiver
• qsimplexmlnodemodel
• qxmlformatter
• qxmlitem
• qxmlname
• qxmlnodemodelindex
• qxmlquery
• qxmlresultitems
• qxmlserializer
• xmlpatternsdiagnosticsts
• xmlpatternsxqts
• xmlpatternsxslts
• qxmlschemavalidator
• qquickxmllistmodel

17:35:01.093 - memPartFree: invalid block 0x808e61fc in partition 0x808eebb0
17:35:01.201 - 0x2066c300 (iTst_checkxmlfiles): tst_checkxmlfiles: memPartFree: invalid block 0x808e61fc in partition 0x808eebb0
17:35:01.201 -  
17:35:01.209 - 0x2066c300 (iTst_checkxmlfiles): RTP 0x2041c010 has had a failure and has been deleted.