Upgrades the thread user_options to 16 bits from an 8-bit value to provide more space for future values. Also, as the size of this field has changed, the values for the existing architecture specific thread options have also shifted from the upper end of the old 8-bit field, to the upper end of the new 16-bit field. Fixes #101034 Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>