The device expression must evaluate to a non-negative integer value.

The device expression must evaluate to a non-negative integer value.

Device clause when it occurs with **target enter data** and **target exit data** must be declared with some non negative value. So some changes were made to evaluate the device clause argument to non negative value and throw the expected error when it takes negative value as argument.

Reviewed By: clementval

Differential Revision: https://reviews.llvm.org/D119141