[wasm] [testing] Allocate a bunch of memory before exiting

[kg]

We seem to be close to the memory limit for some of our test suites, so see whether we can allocate a bunch of memory before exit.

[ghost]

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Issue Details

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We seem to be close to the memory limit for some of our test suites, so see whether we can allocate a bunch of memory before exit.

Author:	kg
Assignees:	-
Labels:	arch-wasm
Milestone:	-

[kg]

Library tests passed with a ~160mb allocation at the end, so it's mysterious that #88279 is maxing out v8's allocated memory at 2gb. I don't know what's going on there, will have to try and come up with theories for how we could be using so much extra memory just from growing the function table.