Implement `nowait`

[scastd]

Describe the feature

The nowait clause allows avoiding the implicit barriers created by some OpenMP directives. It can be used to improve the performance of the code by reducing unnecessary overhead caused due to thread synchronization on the barrier.

OpenMP specification for single construct:

Only the threads of the team that executes the binding parallel region participate in the execution of the structured block and the implied barrier of the single region if the barrier is not eliminated by a nowait clause.

Additional information

• [X] Would you be willing to help implement this feature?

Final checks

• [X] Read the contribution guide.
• [X] Check existing discussions and issues.

[scastd]

This should be easy: create more methods that do not use the Barrier class, with the signature nameNoWait.