Text placement is not redone during rotation

[lucaswoj]

#3490 marks SymbolBucket#collisionBoxArray, SymbolBucket#symbolInstancesArray, SymbolBucket#symbolQuadsArray as transferables. These StructArrays need to be persisted in the workerside SymbolBucket for layer use by SymbolBucket#redoPlacement.

This manifested as a bug in which text would render upside down after the map was rotated.

ref mapbox/mapbox-gl-test-suite#163

cc @jfirebaugh @mourner

Launch Checklist

• briefly describe the changes in this PR
• write tests for all new functionality
• post benchmark scores
• manually test the debug page

[lucaswoj]

I had to add the StructArray#isTransferred property and assert(!this.isTransferred) in order to create a regression test for this bug. When run within mapbox-gl-test-suite, transferred resources do not actually become unavailable.

These assertions should help catch similar bugs in the future. Fail loud 🎺

[mourner]

Sorry, my omission. Glad we'll catch that next time with the new assertions.

Why did you rename trim to _trim?

[jfirebaugh]

Previously: #3365. Does the regression test for that issue catch this one too, providing the additional assertions are added?

[lucaswoj]

You can never blame yourself for breaking something that wasn't tested. No worries.

I renamed StructArray#trim to StructArray#_trim because it isn't called externally anywhere. It used to be called explicitly by Bucket subclasses. I'm a supporter of making public interfaces as small as possible 😄

[lucaswoj]

@jfirebaugh By eyeballing, I think this new regression test would've caught #3365 with or without the new assertions.