fix various typos

src/librustc_codegen_ssa/back/write.rs

@@ -736,7 +736,7 @@ fn execute_work_item<B: ExtraBackendMethods>(
     }
 }
 
-// Actual LTO type we end up chosing based on multiple factors.
+// Actual LTO type we end up choosing based on multiple factors.
 enum ComputedLtoType {
     No,
     Thin,

src/librustc_codegen_ssa/traits/mod.rs

@@ -8,7 +8,7 @@
 //! actual codegen, while the builder stores the information about the function during codegen and
 //! is used to produce the instructions of the backend IR.
 //!
-//! Finaly, a third `Backend` structure has to implement methods related to how codegen information
+//! Finally, a third `Backend` structure has to implement methods related to how codegen information
 //! is passed to the backend, especially for asynchronous compilation.
 //!
 //! The traits contain associated types that are backend-specific, such as the backend's value or