src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java

@@ -100,11 +100,16 @@
     JDK14("14"),
 
     /**
       * 15, tbd
       */
-    JDK15("15");
+    JDK15("15"),
+
+    /**
+      * 16, tbd
+      */
+    JDK16("16");
 
     private static final Context.Key<Source> sourceKey = new Context.Key<>();
 
     public static Source instance(Context context) {
         Source instance = context.get(sourceKey);

@@ -151,10 +156,11 @@
     public boolean isSupported() {
         return this.compareTo(MIN) >= 0;
     }
 
     public Target requiredTarget() {
+        if (this.compareTo(JDK16) >= 0) return Target.JDK1_16;
         if (this.compareTo(JDK15) >= 0) return Target.JDK1_15;
         if (this.compareTo(JDK14) >= 0) return Target.JDK1_14;
         if (this.compareTo(JDK13) >= 0) return Target.JDK1_13;
         if (this.compareTo(JDK12) >= 0) return Target.JDK1_12;
         if (this.compareTo(JDK11) >= 0) return Target.JDK1_11;

@@ -204,13 +210,13 @@
         IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES(JDK1_2, JDK8),
         SWITCH_MULTIPLE_CASE_LABELS(JDK14, Fragments.FeatureMultipleCaseLabels, DiagKind.PLURAL),
         SWITCH_RULE(JDK14, Fragments.FeatureSwitchRules, DiagKind.PLURAL),
         SWITCH_EXPRESSION(JDK14, Fragments.FeatureSwitchExpressions, DiagKind.PLURAL),
         TEXT_BLOCKS(JDK15, Fragments.FeatureTextBlocks, DiagKind.PLURAL),
-        PATTERN_MATCHING_IN_INSTANCEOF(JDK15, Fragments.FeaturePatternMatchingInstanceof, DiagKind.NORMAL),
-        REIFIABLE_TYPES_INSTANCEOF(JDK15, Fragments.FeatureReifiableTypesInstanceof, DiagKind.PLURAL),
-        RECORDS(JDK15, Fragments.FeatureRecords, DiagKind.PLURAL),
+        PATTERN_MATCHING_IN_INSTANCEOF(JDK16, Fragments.FeaturePatternMatchingInstanceof, DiagKind.NORMAL),
+        REIFIABLE_TYPES_INSTANCEOF(JDK16, Fragments.FeatureReifiableTypesInstanceof, DiagKind.PLURAL),
+        RECORDS(JDK16, Fragments.FeatureRecords, DiagKind.PLURAL),
         ;
 
         enum DiagKind {
             NORMAL,
             PLURAL;

@@ -298,10 +304,12 @@
             return RELEASE_13;
         case JDK14:
             return RELEASE_14;
         case JDK15:
             return RELEASE_15;
+        case JDK16:
+            return RELEASE_16;
         default:
             return null;
         }
     }
 }