Add synthetic bridges not in map

Change-Id: I4a2a40df41fa02954ec9ee12c4cc465be9025680
diff --git a/src/main/java/com/android/tools/r8/shaking/Enqueuer.java b/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
index 0f4aa9c..c15fdb8 100644
--- a/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
+++ b/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
@@ -3674,6 +3674,7 @@
     }
     if (methodToKeep != singleTarget
         && !syntheticInterfaceMethodBridges.containsKey(methodToKeep.getDefinition().method)) {
+      syntheticInterfaceMethodBridges.put(methodToKeep.getDefinition().method, methodToKeep);
       assert null == methodToKeep.getHolder().lookupMethod(methodToKeep.getDefinition().method);
       if (singleTargetMethod.isLibraryMethodOverride().isTrue()) {
         methodToKeep.getDefinition().setLibraryMethodOverride(OptionalBool.TRUE);