[SYCL] Fix PIMock initialization in unit tests

[vladimirlaz]

The problem comes from global initialization which is dependent on
another global which happens to be not initialized yet in this case
(the order is non-deterministic by standard).

Global variables causing the issue are moved to static locals in free
functions. That allows to avoid initialization races on usages.

[romanovvlad]

The problem comes from global initialization which is dependent on
another global

Could you please clarify which global initialization and which global?

[vladimirlaz]

The problem comes from global initialization which is dependent on
another global

Could you please clarify which global initialization and which global?

static std::vectordetail::plugin Plugins = pi::initializeAndRemoveInvalid();

another global SyclBeMap

[romanovvlad]

SyclBeMap

I see, thanks. I would also suggest moving SyclBeMap and SyclDeviceTypeMap to the functions where they used to avoid conflicts with them in future.

[vladimirlaz]

SyclBeMap

I see, thanks. I would also suggest moving SyclBeMap and SyclDeviceTypeMap to the functions where they used to avoid conflicts with them in future.

Moved to static locals of free functons.