align experiments.css behavior with webpack when support mini-css-extract-plugin

[hardfist]

Currently we don't align experiments.css behavior with webpack for the following reasons:

• legacy browser support
• custom css module support

both these features can be supported by mini-css-extract-plugin with css-loader, so when we support mini-css-extract-plugin we should consider align with webpack, which includes

• set experiments.css to false by default
• align css chunk loading and code generation logic with webpack

[JSerFeng]

Maybe we should align experiments only after Webpack implements

1. css-module names option
2. exports type can be not only namespace
3. as for the old browser compatibility, Im not sure, better collects voice from community I suppose

Maybe we can co-op with them like making PR for them

Because current css-loader plus css-extrac loader strategy have too much impact for performance

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. If this issue is still affecting you, please leave any comment (for example, "bump"). We are sorry that we haven't been able to prioritize it yet. If you have any new additional information, please include it with your comment!

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. If this issue is still affecting you, please leave any comment (for example, "bump"). We are sorry that we haven't been able to prioritize it yet. If you have any new additional information, please include it with your comment!