anchor.diff:    (Warning_Z3InvocationWarning                       , CWarning);
     (Warning_MissingInterfaceOrImplementation          , CWarning);
     (Warning_ConstructorBuildsUnexpectedType           , CWarning);
  -  (Warning_ModuleOrFileNotFoundWarning               , CWarning)]
  +  (Warning_ModuleOrFileNotFoundWarning               , CWarning);
  +  (Error_BadImplicit                                 , CError)]
   
   exception Err of raw_error* string
   exception Error of raw_error * string * Range.range
  
positive.code:   | Error_UncontrainedUnificationVar
    | Error_UnexpectedGTotComputation
    | Error_UnexpectedInstance
    | Error_BadImplicit
    | Error_UnknownFatal_AssertionFailure
    | Error_Z3InvocationError
    | Error_IDEAssertionFailure
  
negative.code:   | Warning_MissingInterfaceOrImplementation
    | Warning_ConstructorBuildsUnexpectedType
    | Warning_ModuleOrFileNotFoundWarning
    | Error_BadImplicit
  
  // Needs review: Do we need CFatal, or can we just use CError?
  type flag =
    | CError | CFatal | CWarning | CSilent
  
  // This list should be considered STABLE
  // Which means, if you need to add an error, APPEND it, to keep old error numbers the same
  // If an error is deprecated, do not remove it! Change its name (if needed)
  let default_flags =
   [(Error_DependencyAnalysisFailed                    , CError);
    (Error_IDETooManyPops                              , CError);
  