Ensure determinism

[damip]

To make sure execution is deterministic we need to:

• Disable wasm threads support (wasmer frontpage states that it supports wasm threads that are non deterministic )
• Canonicalize NaNs ( https://docs.rs/wasmer-compiler-singlepass-near/latest/wasmer_compiler_singlepass/struct.Singlepass.html#method.canonicalize_nans )
• Limit stack depth to a config defined value (I found this but dunno if it is related: https://docs.rs/wasmer-compiler-singlepass/latest/wasmer_compiler_singlepass/struct.Singlepass.html#method.enable_stack_check )
• Limit memory usage to a config defined value ( see https://github.com/wasmerio/wasmer/blob/c33b89c/examples/tunables_limit_memory.rs )
• look for other sources of nondeterminism (?)

[yvan-sraka]

Could we write stress tests to any of the potential issues described here to see if we're able to produce examples of a bytecode with two runs in identical conditions that end up in different states?

It would be nice to explore the space of all possible SC to find edge cases!