Avoid synthetic methods in Recycler (#9736)
Avoid synthetic methods in Recycler (#9736)

Motivation

Currently the visibility of the various Recycler inner classes and their
fields isn't optimal. Some private members are accessed by other classes
resulting in synthetic methods, and other non-private classes/members
are only accessed privately and so can be made private.

Modifications

- Increase/reduce visibility of various fields/methods/classes within
Recycler
- Have WeakOrderQueue extend WeakReference<Thread> to eliminate the
owner field
- Change local DefaultHandle var to DefaultHandle<?> to avoid raw type
compiler warning

Result

Tidier code, fewer implicit methods on hot paths (reducing inlining
depths)
ejona86/netty,netty/netty,doom369/netty,NiteshKant/netty,zer0se7en/netty,NiteshKant/netty,artgon/netty,johnou/netty,NiteshKant/netty,zer0se7en/netty,doom369/netty,fenik17/netty,andsel/netty,andsel/netty,ejona86/netty,johnou/netty,andsel/netty,Spikhalskiy/netty,NiteshKant/netty,doom369/netty,Spikhalskiy/netty,ejona86/netty,zer0se7en/netty,artgon/netty,doom369/netty,tbrooks8/netty,artgon/netty,fenik17/netty,Spikhalskiy/netty,johnou/netty,netty/netty,Spikhalskiy/netty,zer0se7en/netty,artgon/netty,tbrooks8/netty,johnou/netty,fenik17/netty,NiteshKant/netty,netty/netty,netty/netty,zer0se7en/netty,Spikhalskiy/netty,andsel/netty,artgon/netty,fenik17/netty,fenik17/netty,doom369/netty,ejona86/netty,tbrooks8/netty,tbrooks8/netty,tbrooks8/netty,johnou/netty,andsel/netty,netty/netty,ejona86/netty