v9.5.2-canary.4

Core Changes

• Add missing nomodule polyfills and suggest using features only up to ES2019 for browser compatibility: #15772
• Bug fix: Font optimization: #15644
• Progress bar for static build: #15297
• Incremental static generation and regeneration in build output table: #14365

Misc Changes

• Test that overlay appears: #15850

Credits

Huge thanks to @Timer, @kripod, @prateekbh, @gelbartj, and @darshkpatel for helping!