[jvm-lang] add JvmMetaLanguage

java/java-psi-api/src/com/intellij/lang/jvm/JvmLanguage.java

@@ -0,0 +1,11 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.lang.jvm;
+
+/**
+ * Marker interface for languages which are compiled into JVM-bytecode.
+ *
+ * @see JvmMetaLanguage
+ * @since 2018.2
+ */
+public interface JvmLanguage {
+}

java/java-psi-api/src/com/intellij/lang/jvm/JvmMetaLanguage.java

@@ -0,0 +1,21 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.lang.jvm;
+
+import com.intellij.lang.Language;
+import com.intellij.lang.MetaLanguage;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @since 2018.2
+ */
+public class JvmMetaLanguage extends MetaLanguage {
+
+  protected JvmMetaLanguage() {
+    super("Jvm");
+  }
+
+  @Override
+  public boolean matchesLanguage(@NotNull Language language) {
+    return language instanceof JvmLanguage;
+  }
+}

java/java-psi-impl/src/META-INF/JavaPsiPlugin.xml

@@ -56,6 +56,7 @@
   </extensions>
 
   <extensions defaultExtensionNs="com.intellij">
+    <metaLanguage implementation="com.intellij.lang.jvm.JvmMetaLanguage"/>
     <java.elementFinder implementation="com.intellij.psi.impl.PsiElementFinderImpl" id="java" order="first"/>
     <treeGenerator implementation="com.intellij.psi.impl.source.tree.JavaTreeGenerator"/>
     <itemPresentationProvider forClass="com.intellij.psi.PsiJavaModule"