Do not mark variable access in files without side effects as TDZ

[lukastaegert]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

• resolves Tree-shaking of unused classes is broken #4808

Description

The logic to deoptimize variables when accessed in their temporal dead zone did not take module boundaries into account, leading to falsely deoptimized variables and wrongly attributed side effects.

[netlify]

✅ Deploy Preview for rollupjs ready!

Name	Link
🔨 Latest commit	587510e
🔍 Latest deploy log	https://app.netlify.com/sites/rollupjs/deploys/63f12808c3e46d00083a1dce
😎 Deploy Preview	https://deploy-preview-4866--rollupjs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[github-actions]

Thank you for your contribution! ❤️

You can try out this pull request locally by installing Rollup via

npm install rollup/rollup#gh-4808-cross-module-TDZs

or load it into the REPL:
https://deploy-preview-4866--rollupjs.netlify.app/repl/?pr=4866

[codecov]

Codecov Report

Merging #4866 (587510e) into master (e6148a8) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4866   +/-   ##
=======================================
  Coverage   98.98%   98.98%           
=======================================
  Files         219      219           
  Lines        7943     7943           
  Branches     2189     2188    -1     
=======================================
  Hits         7862     7862           
  Misses         26       26           
  Partials       55       55           

Impacted Files	Coverage Δ
cli/run/batchWarnings.ts	99.17% <ø> (ø)
cli/run/build.ts	90.62% <ø> (ø)
cli/run/index.ts	100.00% <ø> (ø)
cli/run/loadConfigFromCommand.ts	100.00% <ø> (ø)
cli/run/watch-cli.ts	86.11% <ø> (ø)
cli/run/loadConfigFile.ts	96.61% <100.00%> (ø)
src/ast/nodes/Identifier.ts	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[rollup-bot]

This PR has been released as part of rollup@3.17.1. You can test it via npm install rollup.