Vladislav Zavialov authored 2 years ago and Marge Bot committed 2 years ago

Before this patch, GHC unconditionally printed ticks before promoted
data constructors:

	ghci> type T = True  -- unticked (user-written)
	ghci> :kind! T
	T :: Bool
	= 'True              -- ticked (compiler output)

After this patch, GHC prints ticks only when necessary:

	ghci> type F = False    -- unticked (user-written)
	ghci> :kind! F
	F :: Bool
	= False                 -- unticked (compiler output)

	ghci> data False        -- introduce ambiguity
	ghci> :kind! F
	F :: Bool
	= 'False                -- ticked by necessity (compiler output)

The old behavior can be enabled by -fprint-redundant-promotion-ticks.

Summary of changes:
* Rename PrintUnqualified to NamePprCtx
* Add QueryPromotionTick to it
* Consult the GlobalRdrEnv to decide whether to print a tick (see mkPromTick)
* Introduce -fprint-redundant-promotion-ticks

Co-authored-by: Artyom Kuznetsov <hi@wzrd.ht>