add documentation mentions of cranelift-object where appropriate

This change makes it slightly more obvious that `cranelift-object` can
be used in lieu of `cranelift-faerie`.

cranelift/docs/index.rst

@@ -46,6 +46,11 @@ Rust Crate Documentation
     This crate manages compiling multiple functions and data objects
     together.
 
+`cranelift-object <https://docs.rs/cranelift-object/>`_
+    This crate provides a object-based backend for `cranelift-module`, which
+    emits native object files using the
+    `object <https://github.com/gimli-rs/object>`_ library.
+
 `cranelift-faerie <https://docs.rs/cranelift-faerie/>`_
     This crate provides a faerie-based backend for `cranelift-module`, which
     emits native object files using the

cranelift/module/README.md

@@ -13,8 +13,11 @@ following `Backend` implementations:
 
  - `SimpleJITBackend`, provided by [cranelift-simplejit], which JITs
    code to memory for direct execution.
+ - `ObjectBackend`, provided by [cranelift-object], which emits native
+   object files.
  - `FaerieBackend`, provided by [cranelift-faerie], which emits native
    object files.
 
 [cranelift-simplejit]: https://crates.io/crates/cranelift-simplejit
+[cranelift-object]: https://crates.io/crates/cranelift-object
 [cranelift-faerie]: https://crates.io/crates/cranelift-faerie

cranelift/module/src/backend.rs

@@ -17,13 +17,16 @@ use std::string::String;
 
 /// A `Backend` implements the functionality needed to support a `Module`.
 ///
-/// Two notable implementations of this trait are:
+/// Three notable implementations of this trait are:
 ///  - `SimpleJITBackend`, defined in [cranelift-simplejit], which JITs
 ///    the contents of a `Module` to memory which can be directly executed.
+///  - `ObjectBackend`, defined in [cranelift-object], which writes the
+///    contents of a `Module` out as a native object file.
 ///  - `FaerieBackend`, defined in [cranelift-faerie], which writes the
 ///    contents of a `Module` out as a native object file.
 ///
 /// [cranelift-simplejit]: https://docs.rs/cranelift-simplejit/
+/// [cranelift-object]: https://docs.rs/cranelift-object/
 /// [cranelift-faerie]: https://docs.rs/cranelift-faerie/
 pub trait Backend
 where