Note [Wired-in Ids for rebindable syntax]

GHC/Types/Id/Make.hs:2009 compiler

The functions leftSectionId, rightSectionId are
wired in here ONLY because they are used in a representation-polymorphic way
by the rebindable syntax mechanism. See GHC.Rename.Expr
Note [Handling overloaded and rebindable constructs].

Alas, we can't currently give Haskell definitions for
representation-polymorphic functions.

They have Compulsory unfoldings, so that the representation polymorphism
does not linger for long.

References 1

Handling overloaded and rebindable constructs GHC.Rename.Expr

Referenced by 3

GHC.Types.Id.Make call site ×2
Left and right sections GHC.Rename.Expr