Add nightly-only error on ImportType resolution mode assertion

[andrewbranch]

Counterpart to #49002

The reverted commit shows errors that will appear in non-nightly (including the ones from #49002)

Fixes #49354

[andrewbranch]

It should be noted that some of the errors added in this one are in .d.cts files that we generate when the input source did not use a resolution mode assertion.

[andrewbranch]

I think we need to add an emit resolver portability error (with a new error message) whenever the declaration emitter has to produce one of these

[andrewbranch]

First draft:

The type of this expression cannot be named without a resolution mode assertion, which is an unstable feature. Use nightly TypeScript to silence this error. Try updating with 'npm install -D typescript@next'.

[DanielRosenwasser]

The type of this expression cannot be named without a 'resolution-mode' assertion, which is an unstable feature. Use nightly TypeScript to silence this error. Try updating with 'npm install -D typescript@next'.

My minor edits were just that it needs to be wrapped in single quotes, and I would encourage using a hyphen so people can understand what we're talking about better.

[DanielRosenwasser]

Otherwise, I think that's good.

[andrewbranch]

@DanielRosenwasser I was matching this one:

Do you want me to update it too?

[andrewbranch]

Here’s the new portability error in action. Bummer. 🥲

[andrewbranch]

@DanielRosenwasser also this one?

[andrewbranch]

@weswigham mind taking another look since I added some SymbolTracker code?

[andrewbranch]

@typescript-bot cherry-pick this to release-4.7

[typescript-bot]

Heya @andrewbranch, I've started to run the task to cherry-pick this into release-4.7 on this PR at da6f2a6. You can monitor the build here.

[typescript-bot]

Hey @andrewbranch, I couldn't open a PR with the cherry-pick. (You can check the log here). You may need to squash and pick this PR into release-4.7 manually.