Register desugared library dispatch types as synthesized

Change-Id: I1a41caedb9b6fd9c6d0faf3bd7e6ebd0cab4d93c

src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java

diff --git a/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java b/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
index 0e52152..64825c1 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/DesugaredLibraryRetargeter.java
@@ -484,6 +484,6 @@
             + '$'
             + suffix
             + ';';
-    return appView.dexItemFactory().createType(descriptor);
+    return appView.dexItemFactory().createSynthesizedType(descriptor);
   }
 }