Rustfmt and update docs

cranelift/module/src/data_context.rs

@@ -50,7 +50,8 @@ pub struct DataDescription {
     pub data_relocs: Vec<(CodeOffset, ir::GlobalValue, Addend)>,
     /// Object file section
     pub custom_segment_section: Option<(String, String)>,
-    /// Alignment
+    /// Alignment in bytes. `None` means that the default alignment of the respective module should
+    /// be used.
     pub align: Option<u64>,
 }
 

cranelift/module/src/module.rs

@@ -142,7 +142,7 @@ impl FunctionDeclaration {
     }
 }
 
-/// Error messages for all `Module` and `Backend` methods
+/// Error messages for all `Module` methods
 #[derive(Error, Debug)]
 pub enum ModuleError {
     /// Indicates an identifier was used before it was declared