Move TargetKind.displayString from analyzer to meta

Change-Id: Ifa24fb96c97c6b7a2f27794e671672796c56331e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/201460
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analyzer/lib/src/error/best_practices_verifier.dart

@@ -1994,39 +1994,3 @@ class _UsedParameterVisitor extends RecursiveAstVisitor<void> {
     }
   }
 }
-
-extension on TargetKind {
-  /// Return a user visible string used to describe this target kind.
-  String get displayString {
-    switch (this) {
-      case TargetKind.classType:
-        return 'classes';
-      case TargetKind.enumType:
-        return 'enums';
-      case TargetKind.extension:
-        return 'extensions';
-      case TargetKind.field:
-        return 'fields';
-      case TargetKind.function:
-        return 'top-level functions';
-      case TargetKind.library:
-        return 'libraries';
-      case TargetKind.getter:
-        return 'getters';
-      case TargetKind.method:
-        return 'methods';
-      case TargetKind.mixinType:
-        return 'mixins';
-      case TargetKind.parameter:
-        return 'parameters';
-      case TargetKind.setter:
-        return 'setters';
-      case TargetKind.topLevelVariable:
-        return 'top-level variables';
-      case TargetKind.type:
-        return 'types (classes, enums, mixins, or typedefs)';
-      case TargetKind.typedefType:
-        return 'typedefs';
-    }
-  }
-}

pkg/meta/lib/meta_meta.dart

@@ -85,3 +85,39 @@ enum TargetKind {
   /// Indicates that an annotation is valid on any typedef declaration.
   typedefType,
 }
+
+extension TargetKindExtension on TargetKind {
+  /// Return a user visible string used to describe this target kind.
+  String get displayString {
+    switch (this) {
+      case TargetKind.classType:
+        return 'classes';
+      case TargetKind.enumType:
+        return 'enums';
+      case TargetKind.extension:
+        return 'extensions';
+      case TargetKind.field:
+        return 'fields';
+      case TargetKind.function:
+        return 'top-level functions';
+      case TargetKind.library:
+        return 'libraries';
+      case TargetKind.getter:
+        return 'getters';
+      case TargetKind.method:
+        return 'methods';
+      case TargetKind.mixinType:
+        return 'mixins';
+      case TargetKind.parameter:
+        return 'parameters';
+      case TargetKind.setter:
+        return 'setters';
+      case TargetKind.topLevelVariable:
+        return 'top-level variables';
+      case TargetKind.type:
+        return 'types (classes, enums, mixins, or typedefs)';
+      case TargetKind.typedefType:
+        return 'typedefs';
+    }
+  }
+}