Modularize runtime-fields-common (#93719)

This change modulares the runtime-fields-common component by adding a
module-info.java.

relates #78744

modules/runtime-fields-common/src/main/java/module-info.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+module org.elasticsearch.runtimefields {
+    requires org.elasticsearch.base;
+    requires org.elasticsearch.server;
+
+    requires org.elasticsearch.dissect;
+    requires org.elasticsearch.grok;
+    requires org.elasticsearch.painless.spi;
+    requires org.elasticsearch.xcontent;
+
+    requires org.apache.lucene.core;
+
+    exports org.elasticsearch.runtimefields;
+
+    opens org.elasticsearch.runtimefields to org.elasticsearch.painless.spi; // whitelist resource access
+
+    provides org.elasticsearch.painless.spi.PainlessExtension with org.elasticsearch.runtimefields.RuntimeFieldsPainlessExtension;
+}

modules/runtime-fields-common/src/main/java/org/elasticsearch/runtimefields/RuntimeFieldsPainlessExtension.java

@@ -28,6 +28,11 @@ import java.util.Map;
 public class RuntimeFieldsPainlessExtension implements PainlessExtension {
     private final List<Whitelist> whitelists;
 
+    // we don't use ServiceProvider directly, but module-info wants this
+    public RuntimeFieldsPainlessExtension() {
+        throw new UnsupportedOperationException();
+    }
+
     public RuntimeFieldsPainlessExtension(RuntimeFieldsCommonPlugin plugin) {
         Whitelist commonWhitelist = WhitelistLoader.loadFromResourceFiles(RuntimeFieldsPainlessExtension.class, "common_whitelist.txt");
         Whitelist grokWhitelist = new Whitelist(