Revert "Workaround issue with hasOwnProperty"

This reverts commit 8718afe.

src/internal.ts

@@ -24,17 +24,8 @@ export const isLeft = <E, A>(ma: Either<E, A>): ma is Left<E> => ma._tag === 'Le
 // Record
 // -------------------------------------------------------------------------------------
 
-const _hasOwnProperty = Object.prototype.hasOwnProperty
-
-/**
- * This wrapper is needed to workaround https://github.com/gcanti/fp-ts/issues/1249.
- *
- * @internal
- */
-export function hasOwnProperty(this: any, k: string, r?: object) {
-  /* istanbul ignore next */
-  return _hasOwnProperty.call(r === undefined ? this : r, k)
-}
+/** @internal */
+export const hasOwnProperty = Object.prototype.hasOwnProperty
 
 // -------------------------------------------------------------------------------------
 // NonEmptyArray