Adjust Activations for specialise and work/wrap, and better simplify in InlineRules
This patch does two main things:
1. Adjusts the way we set the Activation for
a) The wrappers generated by the strictness analyser
See Note [Wrapper activation] in WorkWrap
b) The RULEs generated by Specialise and SpecConstr
See Note [Auto-specialisation and RULES] in Specialise
Note [Transfer activation] in SpecConstr
2. Refines how we set the phase when simplifying the right
hand side of an InlineRule. See
Note [Simplifying inside InlineRules] in SimplUtils.
Most of the extra lines are comments!
The merit of (2) is that a bit more stuff happens inside InlineRules,
and that in turn allows better dead-code elimination.