TypeScript: reserve unknown as TSUnknownKeyword (#8755)

packages/babel-parser/src/plugins/typescript.js

@@ -57,6 +57,8 @@ function keywordTypeFromName(
       return "TSSymbolKeyword";
     case "undefined":
       return "TSUndefinedKeyword";
+    case "unknown":
+      return "TSUnknownKeyword";
     default:
       return undefined;
   }

packages/babel-parser/src/types.js

@@ -1119,6 +1119,7 @@ export type TsTypeBase = NodeBase;
 
 export type TsKeywordTypeType =
   | "TSAnyKeyword"
+  | "TSUnknownKeyword"
   | "TSNumberKeyword"
   | "TSObjectKeyword"
   | "TSBooleanKeyword"

packages/babel-parser/test/fixtures/typescript/types/keywords/input.js

@@ -1,4 +1,5 @@
 let a: any;
+let un: unknown;
 let b: boolean;
 let ne: never;
 let nul: null;