Fix typos “a”→“an”

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1697,7 +1697,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
 
         // In some (most?) cases cause.body_id points to actual body, but in some cases
-        // it's a actual definition. According to the comments (e.g. in
+        // it's an actual definition. According to the comments (e.g. in
         // librustc_typeck/check/compare_method.rs:compare_predicate_entailment) the latter
         // is relied upon by some other code. This might (or might not) need cleanup.
         let body_owner_def_id =

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -389,7 +389,7 @@ where
     }
 }
 
-/// When we instantiate a inference variable with a value in
+/// When we instantiate an inference variable with a value in
 /// `relate_ty_var`, we always have the pair of a `TyVid` and a `Ty`,
 /// but the ordering may vary (depending on whether the inference
 /// variable was found on the `a` or `b` sides). Therefore, this trait

compiler/rustc_infer/src/infer/region_constraints/mod.rs

@@ -186,7 +186,7 @@ pub enum GenericKind<'tcx> {
 ///        ('a: min) || ('b: min)
 ///     }
 ///
-/// This is described with a `AnyRegion('a, 'b)` node.
+/// This is described with an `AnyRegion('a, 'b)` node.
 #[derive(Debug, Clone)]
 pub enum VerifyBound<'tcx> {
     /// Given a kind K and a bound B, expands to a function like the

compiler/rustc_infer/src/traits/mod.rs

@@ -28,7 +28,7 @@ pub use self::project::{
 pub use rustc_middle::traits::*;
 
 /// An `Obligation` represents some trait reference (e.g., `i32: Eq`) for
-/// which the "impl_source" must be found. The process of finding a "impl_source" is
+/// which the "impl_source" must be found. The process of finding an "impl_source" is
 /// called "resolving" the `Obligation`. This process consists of
 /// either identifying an `impl` (e.g., `impl Eq for i32`) that
 /// satisfies the obligation, or else finding a bound that is in