Update faerie, remove usage of failure (#591)

This commit removes the usage of the `failure` crate and finishes up the
final pieces of the migration to `std::error::Error` and `anyhow`. The
`faerie` crate was updated to pull in its migration from `failure` to
`anyhow` as well.

crates/debug/src/transform/mod.rs

@@ -1,7 +1,7 @@
 use crate::gc::build_dependencies;
 use crate::{DebugInfoData, HashSet};
+use anyhow::Error;
 use cranelift_codegen::isa::TargetFrontendConfig;
-use failure::Error;
 use gimli::{
     write, DebugAddr, DebugAddrBase, DebugLine, DebugStr, LocationLists, RangeLists,
     UnitSectionOffset,