fix(language-service): use empty statement as parent of type node (#3…

…6989)

In TypeScript 3.9, type nodes need to exist in the context of a statement.
This commit ensures that the synthetic type node has such a parent.

PR Close #36989

packages/language-service/src/typescript_symbols.ts

@@ -827,7 +827,7 @@ function getTsTypeFromBuiltinType(builtinType: BuiltinType, ctx: TypeContext): t
           `Internal error, unhandled literal kind ${builtinType}:${BuiltinType[builtinType]}`);
   }
   const node = ts.createNode(syntaxKind);
-  node.parent = ctx.node;
+  node.parent = ts.createEmptyStatement();
   return ctx.checker.getTypeAtLocation(node);
 }