Fixes #498 - Extend progvar_prog_scope_uninit checks (#544)
Fixes #498 - Extend progvar_prog_scope_uninit checks (#544)

This adds checks to progvar_prog_scope_uninit which ensure that
program-scope variables are default-initialized to the zero-value for
their type.
KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS,KhronosGroup/OpenCL-CTS