Fix missing overrides

Change-Id: I37f20f69987f9dad343beb20a97f426ba7927dfe
diff --git a/src/main/java/com/android/tools/r8/cf/code/CfInvoke.java b/src/main/java/com/android/tools/r8/cf/code/CfInvoke.java
index 4153c0b..b725c80 100644
--- a/src/main/java/com/android/tools/r8/cf/code/CfInvoke.java
+++ b/src/main/java/com/android/tools/r8/cf/code/CfInvoke.java
@@ -189,6 +189,7 @@
     return opcode == Opcodes.INVOKEVIRTUAL;
   }
 
+  @Override
   public boolean isInvokeInterface() {
     return opcode == Opcodes.INVOKEINTERFACE;
   }
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/BufferCovariantReturnTypeRewriter.java b/src/main/java/com/android/tools/r8/ir/desugar/BufferCovariantReturnTypeRewriter.java
index 8678041..0f264b0 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/BufferCovariantReturnTypeRewriter.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/BufferCovariantReturnTypeRewriter.java
@@ -30,6 +30,7 @@
     this.factory = appView.dexItemFactory();
   }
 
+  @Override
   public Collection<CfInstruction> desugarInstruction(
       CfInstruction instruction,
       FreshLocalProvider freshLocalProvider,