Assign annotation to intellij-core library

.idea/libraries/intellij_core.xml

@@ -1,5 +1,8 @@
 <component name="libraryTable">
   <library name="intellij-core">
+    <ANNOTATIONS>
+      <root url="file://$PROJECT_DIR$/annotations" />
+    </ANNOTATIONS>
     <CLASSES>
       <root url="file://$PROJECT_DIR$/ideaSDK/core" />
       <root url="jar://$PROJECT_DIR$/dependencies/cli-parser-1.1.1.jar!/" />

build.xml

@@ -316,7 +316,7 @@
         <cleandir dir="${output}/classes/compiler"/>
 
         <javac2 destdir="${output}/classes/compiler" debug="true" debuglevel="lines,vars,source" includeAntRuntime="false" source="${java.target}" target="${java.target}">
-            <withKotlin/>
+            <withKotlin externalannotations="${external.annotations.path}"/>
             <src refid="compilerSources.path"/>
             <classpath refid="classpath"/>
         </javac2>