Move cranelift dependencies to wasmtime-environ (#669)

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

crates/debug/src/transform/line_program.rs

@@ -2,13 +2,13 @@ use super::address_transform::AddressTransform;
 use super::attr::clone_attr_string;
 use super::{Reader, TransformError};
 use anyhow::Error;
-use cranelift_entity::EntityRef;
 use gimli::{
     write, DebugLine, DebugLineOffset, DebugStr, DebuggingInformationEntry, LineEncoding, Unit,
 };
 use more_asserts::assert_le;
 use std::collections::BTreeMap;
 use std::iter::FromIterator;
+use wasmtime_environ::entity::EntityRef;
 
 #[derive(Debug)]
 enum SavedLineProgramRow {