RTS: Add setInCallCapability()

Authored by simonmar on Nov 18 2014, 9:44 AM.

Description

RTS: Add setInCallCapability()

This allows an OS thread to specify which capability it should run on
when it makes a call into Haskell. It is intended for a fairly
specialised use case, when the client wants to have tighter control over
the mapping between OS threads and Capabilities - perhaps 1:1
correspondence, for example.

Details