Exception backtrace proposal prerequisites
This includes a number of changes preparing for the exception backtrace proposal.
These include:
- Microoptimisation in
HasCallStack
evidence generation noticed while implementing defaulting - Clean-up uses of
SomeException
incompiler
- Move
PrimMVar
andnewStablePtrPrimMVar
toGHC.MVar
such thatGHC.Stack.CloneStack
no longer depends uponControl.Concurrent.MVar
- Move
prettyCallStack
intoGHC.Stack
such that it can be used in comingExceptionAnnotation
instances - Implement CLC#198, teaching the top-level exception handler to use
displayException
rather thanshow