DynFlags: remove use of sdocWithDynFlags from GHC.Stg.* (#17957)
- add StgPprOpts datatype
- remove Outputable instances for types that need
StgPprOpts
to be pretty-printed and explicitly call type specific ppr functions - add default
panicStgPprOpts
for panic messages (when it's not convenient to thread StgPprOpts or DynFlags down to the ppr function call)