Bug 251330

https://github.com/WebAssembly/gc/blob/main/proposals/gc/MVP.md implies that arrays of vectors should be supported, e.g. the description of `array.new_canon_data`: "t' is numeric, vector, or packed". That implies that `array.get` and `array.set` should work on arrays of vectors. However, this functionality is currently not implemented in the `JSWebAssemblyArray` class (see the implementations of `get()` and `set()`.) The AIR implementations of `array.new_canon` and `array.get` also use `emitCoerceFromI64` on the input or result value, which crashes with an assertion failure when the source type is `v128`.