Allow setting processor affinity for spawned processes

[Rohansi]

Details

There is currently no way to set the processor affinity for spawned processes. Being able to set the affinity is useful in some scenarios to prevent a child process from starving something else of CPU resources.

Checklist

• I have looked through existing issues to make sure that this feature has not been requested before
• I have provided a descriptive title for this issue
• I am aware that even valid feature requests may be rejected if they do not align with the project's goals
• I have sponsored this project