Add support for export defer, when it lands #2621
Description
Initial checklist
- I read the support docs
- I read the contributing guide
- I agree to follow the code of conduct
- I searched issues and discussions and couldn’t find anything (or linked relevant results below)
Problem
https://tc39.es/proposal-deferred-reexports/#sec-exports
it’s being added to the AST over on estree/estree.
Current solutions
none
Proposed solutions
When it lands in estree and when it is in acorn and astring, add it here, and test everywhere.