diff -r c32c9586ea94 -r aa84b6606229 langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java	Mon Sep 08 10:50:59 2014 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java	Mon Sep 08 13:11:28 2014 +0200
@@ -1588,6 +1588,8 @@
             return TypeAnnotationPosition.methodReturn(readTypePath());
         case FIELD:
             return TypeAnnotationPosition.field(readTypePath());
+        case UNKNOWN:
+            throw new AssertionError("jvm.ClassReader: UNKNOWN target type should never occur!");
         default:
             throw new AssertionError("jvm.ClassReader: Unknown target type for position: " + type);
         }