Remove Unsafe Dynflags deadcode, they don't exist any more!

[fendor]

I am currently reading through the ghcide code, and I noticed some supposed dead code, as unsafeDynFlags don't exist any more, setUnsafeDynFlags (and for 9.4.8) just sets a couple of Outputable IORefs, which we likely don't want/need.

Thus, just delete and see whether CI is happy.

[soulomoon]

Looking good at CI but, it seems effect https://gitlab.haskell.org/ghc/ghc/-/blob/59202c800f2c97c16906120ab2561f6e1556e4af/compiler/GHC/Utils/Trace.hs#L42 ?
Do we have another place passing in the setting for dynFlagsForPrinting?

[fendor]

All SDocs we produce, should have a reference to SDocContext which are produced from the DynFlags respective to each component. GHC was changed in the past to move towards this SDocContext instead of unsafeGlobalDynFlags to avoid this global state. Thus, not relying on these globals is more correct than before, in my opinion, even though I think we are not even using them at all.
I don't think we need to call dynFlagsForPrinting ourselves, as we are not doing anything with the produced DynFlags. In hiedb, dynFlagsForPrinting essentially creates the default DynFlags, and then uses these to initialise the SDocContext when printing AST nodes. Since it is the default DynFlags, we are effectively initialising the global variables from the default DynFlags, which I think will be the same values for the global variables any way.

[soulomoon]

Thanks for the explaination, make sense to me !