00a4e93bcd
This adds a feature which allows one to look up an export by name without knowing what module it's in -- `lookup_global_export` on an `InstanceContents`. The main expected use for this is to support APIs where module A imports a function from module B, and module B needs to access module A's memory. B can't import it from A in the normal way, because that would create a dependency cycle. So for now, allow B to look up A's exported memory dynamically with `lookup_global_export`. In the future, with reference types and possibly host bindings, we'll be able to pass references to memory as arguments, which will obviate the need for this mechanism.
This is the wasmtime-runtime crate, which contains wasm runtime library
support, supporting the wasm ABI used by wasmtime-environ,
wasmtime-jit, and wasmtime-obj.
This crate does not make a host vs. target distinction; it is meant to be compiled for the target.