 These @-d\<blah\>@ flags can all be reversed with @-dno-\<blah\>@
dFlags :: [FlagSpec GeneralFlag]
dFlags = [
  ( "suppress-coercions",               Opt_SuppressCoercions,          nop),
  ( "suppress-var-kinds",               Opt_SuppressVarKinds,           nop),
  ( "suppress-module-prefixes",         Opt_SuppressModulePrefixes,     nop),
  ( "suppress-type-applications",       Opt_SuppressTypeApplications,   nop),
  ( "suppress-idinfo",                  Opt_SuppressIdInfo,             nop),
  ( "suppress-type-signatures",         Opt_SuppressTypeSignatures,     nop),
  ( "suppress-uniques",                 Opt_SuppressUniques,            nop),
  ( "ppr-case-as-let",                  Opt_PprCaseAsLet,               nop)]

--
dFlags :: [FlagSpec GeneralFlag]
dFlags = [
  ( "suppress-coercions",               Opt_SuppressCoercions,          nop),
  ( "suppress-var-kinds",               Opt_SuppressVarKinds,           nop),
  ( "suppress-module-prefixes",         Opt_SuppressModulePrefixes,     nop),
  ( "suppress-type-applications",       Opt_SuppressTypeApplications,   nop),
  ( "suppress-idinfo",                  Opt_SuppressIdInfo,             nop),
  ( "suppress-type-signatures",         Opt_SuppressTypeSignatures,     nop),
  ( "suppress-uniques",                 Opt_SuppressUniques,            nop),
  ( "ppr-case-as-let",                  Opt_PprCaseAsLet,               nop)]
dFlags = [
  ( "suppress-coercions",               Opt_SuppressCoercions,          nop),
  ( "suppress-var-kinds",               Opt_SuppressVarKinds,           nop),
  ( "suppress-module-prefixes",         Opt_SuppressModulePrefixes,     nop),
  ( "suppress-type-applications",       Opt_SuppressTypeApplications,   nop),
  ( "suppress-idinfo",                  Opt_SuppressIdInfo,             nop),
  ( "suppress-type-signatures",         Opt_SuppressTypeSignatures,     nop),
  ( "suppress-uniques",                 Opt_SuppressUniques,            nop),
  ( "ppr-case-as-let",                  Opt_PprCaseAsLet,               nop)]