[Go] posix thread TLS(slow) call by Go

Thread Local Storage(TLS)  is slow. (TLPI Ch.31.3.1, Ch.31.4)

Discussion thread:
https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/golang-nuts/tGamryo50BY/gKxPGwBdAwAJ


Steps:

1. Using runtime.LockOSThread to lock this go-routine to the underlying P
2. Call cgo/c SO.
3. Use channel to pass down messages, other go-routine might be scheduled out of this P(most likely won't if listen to same channel)