(2.11) Internal: Small udpates to ipQueue

[kozlovic]

Small updates to ipQueue:

• Document that caller must not reuse the slice after call to recycle().
• Reset size to 0 on pop() or last popOne() without need to call q.caclc().
• Added missing recycle() calls in some places.
• Added benchmarks to check perf impact on future changes.

Signed-off-by: Ivan Kozlovic [email protected]

[kozlovic]

@neilalexander As discussed in the other PR, I am splitting changes to ipQueue starting with this one, that contains small updates. I ended-up keeping []T for pop() (which also minimize changes) and simply document that one must not reuse the slice after recycle(), which, after thinking about it makes sense. Anything that is put back into a pool must not be reused by the caller, since the pool owns it now, and is then used by other code after a Get().