Log Message:
Update to th-abstraction-0.4.2.0

0.4.2.0 -- 2020-12-30
* Explicitly mark modules as Safe (or Trustworthy for GHC versions
  prior to 8.4).

0.4.1.0 -- 2020-12-09
* Fix a bug in which normalizeDec would give incorrect kind
  annotations to type variables in quoted Decs. normalizeDec now
  leaves the kinds of type variable binders alone.

0.4.0.0 -- 2020-09-29
* Adapt to the TyVarBndr data type gaining a new flag type parameter
  (in template-haskell-2.17.0.0) to represent its specificity:
* Introduce a new Language.Haskell.TH.Datatype.TyVarBndr module that
  defines TyVarBndr_, a backwards-compatible type synonym for
  TyVarBndr, as well as backporting TyVarBndrSpec, TyVarBndrUnit, and
  Specificity. This module also defines other useful functions for
  constructing and manipulating TyVarBndrs.
* The types in Language.Haskell.TH.Datatype now use TyVarBndr_,
  TyVarBndrUnit, and TyVarBndrSpec where appropriate. Technically,
  this is not a breaking change, since all three are simple type
  synonyms around TyVarBndr, but it is likely that you will need to
  update your th-abstraction-using code anyway if it involves a
  TyVarBndr-consuming function.

0.3.2.0 -- 2020-02-06
* Support substituting into and extracting free variables from
  ForallVisTs on template-haskell-2.16.0.0 (GHC 8.10) or later.
* Fix a bug in which freeVariables could report duplicate kind
  variables when they occur in the kinds of the type variable binders
  in a ForallT.
* Fix a bug in which resolveInfixT would not resolve UInfixTs
  occurring in the kinds of type variable binders in a ForallT.
* Fix a bug in which the TypeSubstitution ConstructorInfo instance
  would not detect free kind variables in the constructorVars.