C#: Improve comments.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs

@@ -26,7 +26,7 @@ public static bool ConstructedOrParentIsConstructed(INamedTypeSymbol symbol)
         }
 
         /// <summary>
-        /// Returns true in case we suspect this is broken type.
+        /// Returns true in case we suspect this is a broken type.
         /// </summary>
         /// <param name="symbol">Type symbol</param>
         private bool IsBrokenType(ITypeSymbol symbol)
@@ -38,8 +38,8 @@ private bool IsBrokenType(ITypeSymbol symbol)
                 return false;
             }
 
-            // (1) public class { ... } is a broken type and doesn't have a name.
-            // (2) public class var { ... } is a an allowed type, but it overrides the var keyword for all uses.
+            // (1) public class { ... } is a broken type as it doesn't have a name.
+            // (2) public class var { ... } is an allowed type, but it overrides the `var` keyword for all uses.
             //     It is probably a better heuristic to treat it as a broken type.
             return string.IsNullOrEmpty(symbol.Name) || symbol.Name == "var";
         }

csharp/ql/test/library-tests/standalone/brokentypes/BrokenTypes.cs

@@ -18,7 +18,7 @@ public static void Main()
         string y1 = x1.Prop;
 
         var x2 = new C(); // Has type `var` as this overrides the implicitly typed keyword `var`.
-        var y2 = x2.Prop; // Unknown type as `x2` har type `var`.
+        var y2 = x2.Prop; // Unknown type as `x2` has type `var`.
 
         C2 x3 = new C2(); // Unknown type.
         var y3 = x3.Prop; // Unknown property of unknown type.