EPA: Use less cryptic names for EpaAnchor constructors
Arising from #19579 and !2418 (comment 338142)
At the moment EpaAnchor
is defined with short, cryptic constructors as
data EpaAnchor = AR RealSrcSpan
| AD DeltaPos
deriving (Data,Show,Eq,Ord)
Change it to
data EpaAnchor = AnchorReal RealSrcSpan
| AnchorDelta DeltaPos
deriving (Data,Show,Eq,Ord)