Running studio runtime in ROM only environments.

In some HW environments like instrument clusters there may not be permanent writable storage or/and a filesystem.

If the runtime is going to be used in such environment we need to check that everything works without having to write items to disk.

Issues that that least I can think of:

• No filesystem and QProcess won't start due to pipe not working.
• Shader caching, we need to precompile the shaders to bins and add them to resource.
• Use QtQuickCompiler instead of QML caching
  • JIT?? JIT is not working on the system I tested (Integrity ARM 64bit).
• QSettings, dump the settings to .ini and use that for loading.
• Network issues? mainly sockets if needed. for Instrument cluster check CAN functionality.
• If ramdisk is only a blockdevice or without FS should we have virtual filesystem (like in Qt4). It should be possible to run the system without any write needs, but having something writable to be able to run the Qt3dsViewer as remote makes it easier to test on the HW.

On upside such system where there is no stored permanent state is more robust.

Other than the QProcess issue I think most of these can be solved without changes to Qt unless we want to add convenience/make runtime 'ROM ready'.