Thread Local Storage

[dennwc]

cxgo doesn't support thread local storage yet.

We can emulate it by passing a *TLS object to all the functions that use it, and to all their callers, similar to how context.Context is passed in Go.

[g41797]

Goroutine local storage: https://github.com/jtolio/gls Fast goroutine local storage:https://github.com/cosmos72/gls