[wasm] Try to get sharding working for ICU

[CoffeeFlux]

We tried this previously and ran into issues, but things might now be more stable. This would potentially enable us to better split up the ICU data files.

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Issue Details

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We tried this previously and ran into issues, but things might now be more stable. This would potentially enable us to better split up the ICU data files.

Author:	CoffeeFlux
Assignees:	lewing
Labels:	arch-wasm, area-System.Globalization, size-reduction
Milestone:	6.0.0

[CoffeeFlux]

Doc on this should be available by Friday

[CoffeeFlux]

Sharding works, but the actual split is left as part of #49221