x/mobile/bind: support slices of structs

[kevmo314]

Adds code generation for supporting slices of structs in gobind.

Fixes golang/go#13445

NOTE: This PR isn't quite done yet, I'm having some trouble getting the testing environment set up. It seems like the default test environment is a bit outdated? In any case, could I use this PR's CI to iterate on test failures? Open to other suggestions as well.

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Patch Set 1:

(1 comment)

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