Memory leak when using QML FileDialog

Microsoft Application Verifier reports two errors when QML FileDialog is used:

• ErrorCode 61D: Creating executable heap; when opening FileDialog
• ErrorCode 900: A heap allocation was leaked; when closing an application

The problem can be reproduced with Qt Example System Dialogs Gallery. Steps to reproduce:
1. Add systemdialogs.exe to Application Verifier and enable Basic > Leak and Memory, and enable ExecWritePage of Memory (Select Memory > Right click of mouse > Properties)
2. Execute systemdialogs.exe from WinDbg
3. When System Dialogs Gallery example application is up and running, open file (File tab > Open)
4. "ErrorCode 61D: Creating executable heap" is shown in WinDbg
5. Close the FileDialog and the application
6. "ErrorCode 900: A heap allocation was leaked" is shown

Note: Heap allocation leak doesn't happen when QFileDialog is used.

See attached qtbug_detailed_instructions.txt for more detailed steps to reproduce and full error texts.