Unresolvable runtime helper modules after upgrading to v7.7.5

[rwjblue]

Bug Report

#10549 introduced a bit of breakage to consumers of ember-cli-babel.

When using @babel/plugin-transform-modules-amd to transpile the runtime helpers (from @babel/runtime/helpers/esm) into AMD modules, the resulting define statement's do not include the .js extension. However, when using @babel/plugin-transform-runtime@7.7.5 (which includes #10549) along with useESModules: true the import statements will include .js which results in "module not found" errors.

[rwjblue]

I'm happy to work on changes to ember-cli-babel to accommodate this change, but wanted to open an issue here to discuss (in case other communities are affected as well).