CR feedback

src/Compilers/CSharp/Portable/Lowering/AsyncRewriter/AwaitExpressionSpiller.cs

@@ -384,7 +384,7 @@ private BoundStatement UpdateStatement(BoundSpillSequenceBuilder builder, BoundS
                         //       - `RefKind.In`                     (specified with no modifiers and matched an 'In' parameter)
                         //
                         //       It is allowed to spill ordinary `In` arguments by value if reference-preserving spilling is not possible.
-                        //       The "strct" ones do not permit implicit copying, so the same situation should result in an error.
+                        //       The "strict" ones do not permit implicit copying, so the same situation should result in an error.
                         if (refKind != RefKind.None && refKind != RefKind.In)
                         {
                             Debug.Assert(call.Method.RefKind != RefKind.None);
@@ -401,7 +401,7 @@ private BoundStatement UpdateStatement(BoundSpillSequenceBuilder builder, BoundS
                         //       - `RefKind.In`                     (specified with no modifiers and matched an 'In' parameter)
                         //
                         //       It is allowed to spill ordinary `In` arguments by value if reference-preserving spilling is not possible.
-                        //       The "strct" ones do not permit implicit copying, so the same situation should result in an error.
+                        //       The "strict" ones do not permit implicit copying, so the same situation should result in an error.
                         if (refKind != RefKind.None && refKind != RefKind.RefReadOnly)
                         {
                             Debug.Assert(conditional.IsByRef);

src/Compilers/CSharp/Portable/Lowering/LocalRewriter/LocalRewriter_Call.cs

@@ -526,7 +526,7 @@ private static ImmutableArray<RefKind> GetEffectiveArgumentRefKinds(ImmutableArr
                         }
                     }
 
-                    refKindsBuilder[i] = argRefKind == RefKind.None? paramRefKind: RefKindExtensions.StrictIn;
+                    refKindsBuilder[i] = argRefKind == RefKind.None ? paramRefKind : RefKindExtensions.StrictIn;
                 }
             }
 

src/Compilers/Core/Portable/Symbols/RefKind.cs

@@ -34,6 +34,10 @@ public enum RefKind : byte
         /// Indicates a "ref readonly" return type.
         /// </summary>
         RefReadOnly = 3,
+
+        // NOTE: There is an additional value of this enum type - RefKindExtensions.StrictIn == RefKind.In + 1
+        //       It is used internally during lowering. 
+        //       Consider that when adding values or changing this enum in some other way.
     }
 
     internal static class RefKindExtensions
@@ -55,7 +59,7 @@ internal static string ToArgumentDisplayString(this RefKind kind)
             {
                 case RefKind.Out: return "out";
                 case RefKind.Ref: return "ref";
-                case RefKind.RefReadOnly: return "in";
+                case RefKind.In: return "in";
                 default: throw ExceptionUtilities.UnexpectedValue(kind);
             }
         }
@@ -75,6 +79,6 @@ internal static string ToParameterPrefix(this RefKind kind)
         // used internally to track `In` arguments that were specified with `In` modifier
         // as opposed to those that were specified with no modifiers and matched `In` parameter
         // There is at least one kind of anlysis that cares about this distinction - async stack spilling
-        internal const RefKind StrictIn = (RefKind)(RefKind.In + 1);
+        internal const RefKind StrictIn = RefKind.In + 1;
     }
 }