* Fix compilation of wasmtime-environ from within wasmtime-jit. Enable wasmtime-environ/std when wasmtime-jit's std feature is enabled. Fixes #200. * Fix wasmtime-debug build too.
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.