Function 'finally' on prototype shouldn't polyfill 'promise'

[chenjianzhonglol]

When i define a 'finally' function on other function's prototype, why dist code includes "core-js/modules/es.promise.finally.js",
"core-js/modules/es.promise.js".

ex:

[JLHwung]

I think we can skip the MemberExpression path if the it is in the left of an AssignmentExpression whose operator is =?

babel-polyfills/packages/babel-helper-define-polyfill-provider/src/visitors/usage.js

Line 27 in 615e5cd

MemberExpression(path: NodePath) {

[nicolo-ribaudo]

It would work, even if somewhere that .finally method is probably used so the es.promise.finally polyfill will be added anyway.

I wonder why we add the polyfill for

function Test() {}

Test.prototype.finally = function() {}

but not for

Test.prototype.finally = function() {}

[zloirock]

I think we can skip the MemberExpression path

It will break the monkey patching of built-in methods in some cases, for example testing.