backport fixes for #541

Author: zloirock

CHANGELOG.md

@@ -1,4 +1,7 @@
 ## Changelog
+##### 2.6.6 [LEGACY]
+- Fixed IE8- non-enumerable properties support in `Object.{ assign, entries, values }`, [#541](https://github.com/zloirock/core-js/issues/541)
+
 ##### 2.6.5 - 2019.02.15
 - Fixed buggy `String#padStart` and `String#padEnd` mobile Safari implementations, [#414](https://github.com/zloirock/core-js/issues/414).