IE11: Cannot define property 'name': object is not extensible

[glortho]

When using es6.function.name (and es6.symbol) in IE11 there appear to be some circumstances where dP(this, NAME, createDesc(5, name)) in https://github.com/zloirock/core-js/blob/master/modules/es6.function.name.js#L13 throws the above error, presumably because the object has been frozen or sealed.

One such case where this happens is in certain accesses of componentClass.name here: https://github.com/facebook/react/blob/67f8524e88abbf1ac0fd86d38a0477d11fbc7b3e/src/isomorphic/classic/element/ReactElementValidator.js#L237 .

This approach is a safer alternative, though with some obvious drawbacks by comparison: https://github.com/JamesMGreene/Function.name/blob/master/Function.name.js

[zloirock]

Ok, I will add a fallback for frozen functions.