Move cranelift dependencies to wasmtime-environ (#669)

Groups all CL data structures into single dependency to be used accross wasmtime project.

crates/jit/src/lib.rs

@@ -32,6 +32,9 @@ mod namespace;
 mod resolver;
 mod target_tunables;
 
+pub mod native;
+pub mod trampoline;
+
 pub use crate::action::{ActionError, ActionOutcome, RuntimeValue};
 pub use crate::code_memory::CodeMemory;
 pub use crate::compiler::{CompilationStrategy, Compiler};