JS: Fix polarity of alias check

Author: asgerf

javascript/extractor/lib/typescript/src/type_table.ts

@@ -867,7 +867,7 @@ export class TypeTable {
       } else {
         typeExtractionState[id] = TypeExtractionState.DoneFull;
         this.isInShallowTypeContext = isShallowContext || this.isExpansiveTypeReference(type);
-        if (type.aliasSymbol != null) {
+        if (type.aliasSymbol == null) {
           this.extractProperties(type, id);
           this.extractSignatures(type, id);
           this.extractIndexers(type, id);