Don't set min-api if the dump compile is to CF.

R=ricow

Change-Id: I7bac7b9387720c8b6c945b227688c19421006b2d
diff --git a/src/main/java/com/android/tools/r8/utils/CompileDumpCompatR8.java b/src/main/java/com/android/tools/r8/utils/CompileDumpCompatR8.java
index e349c9a..c230a6d 100644
--- a/src/main/java/com/android/tools/r8/utils/CompileDumpCompatR8.java
+++ b/src/main/java/com/android/tools/r8/utils/CompileDumpCompatR8.java
@@ -171,8 +171,10 @@
             .addClasspathFiles(classpath)
             .addProguardConfigurationFiles(config)
             .setOutput(outputPath, outputMode)
-            .setMode(compilationMode)
-            .setMinApiLevel(minApi);
+            .setMode(compilationMode);
+    if (outputMode != OutputMode.ClassFile) {
+      commandBuilder.setMinApiLevel(minApi);
+    }
     features.forEach(
         (in, out) ->
             commandBuilder.addFeatureSplit(