[WIP] ReFinalize GlobalGet in initializers after GlobalRefining

[tlively]

When GlobalRefining refines the type of a global, it updates the type of corresponding GlobalGet expressions, then runs ReFinalize to propagate the refined types. However, it only performed these updates in function bodies, leaving stale types on GlobalGet expressions in constant initializers. This bug was not easily caught because the validator did not check that GlobalGet types actually match the types of the corresponding globals.

Fix the validator to check the types of GlobalGet expressions and fix GlobalRefining to properly update constant initializers.

Fixes #6565.

[tlively]

• #6566 👈
• main

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[tlively]

So far this fixes the validator and adds a failing test, but does not actually fix GlobalRefining yet. Once GlobalRefining is fixed to refinalize global initializers, it will open up the possibility of further refining the globals whose initializers depend on previously refined globals. @kripken, do you think it is worth iterating to a fixed point in this pass?

[kripken]

Good find! Yeah, when we are missing validation then these bugs can be hard to figure out (and my guess at the cause here was way off...).

Iterating to a fixed point makes sense I think, unless there is some complexity I am missing.

[tlively]

Superseded by #6603