Move all trampoline compilation to wasmtime-cranelift (#3176)

* Move all trampoline compilation to `wasmtime-cranelift`

This commit moves compilation of all the trampolines used in wasmtime
behind the `Compiler` trait object to live in `wasmtime-cranelift`. The
long-term goal of this is to enable depending on cranelift *only* from
the `wasmtime-cranelift` crate, so by moving these dependencies we
should make that a little more flexible.

* Fix windows build

crates/environ/src/data_structures.rs

@@ -17,7 +17,7 @@ pub mod settings {
 
 pub mod isa {
     pub use cranelift_codegen::isa::{
-        unwind, Builder, CallConv, RegUnit, TargetFrontendConfig, TargetIsa,
+        lookup, unwind, Builder, CallConv, RegUnit, TargetFrontendConfig, TargetIsa,
     };
 }