Task API provides no mechanism to provide an instance parameter

[BrianSipos]

Is your feature request related to a problem? Please describe.
There is currently no way to provide a runtime parameter to a task that is visible to the specific function executed in the task thread.

Describe the solution you'd like
Both POSIX and RTEMS provide the ability to provide a single task function argument in the form of an opaque pointer (RTEMS isn't typed as a pointer but has a guaranteed size able to hold a pointer).

Describe alternatives you've considered
Without a mechanism to give a parameter to a task function, the only way to provide task-instance-specific data is some kind of an external thread-safe queue for each task function, and all of the excess bookkeeping required for that queue.

Requester Info
Brian Sipos, JHU/APL