Previously each module in a module-linking-using-module would compile all the trampolines for all signatures for all modules. In forest-like situations with lots of modules this would cause quite a few trampolines to get compiled. The original intention was to have one global list of trampolines for all modules in the module-linking graph that they could all share. With the current design of module linking, however, the intention is for modules to be relatively isolated from one another which would make achieving this difficult. In lieu of total sharing (which would be good for the global scope anyway but we also don't do that right now) this commit implements an alternative strategy where each module simply compiles its own trampolines that it itself can reach. This should mean that module-linking modules behave more similarly to standalone modules in terms of trampoline duplication. If we ever do global trampoline deduplication we can likely batch this all together into one, but for now this should fix the performance issues seen in fuzzing. Closes #2525
This is the wasmtime-jit crate, which contains JIT-based execution
for wasm, using the wasm ABI defined by wasmtime-environ and the
runtime support provided by wasmtime-runtime.
Most users will want to use the main wasmtime crate instead of using this
crate directly.