Version 8.2.57

Fix git merge issue.

Change-Id: I768777987f447173d92e0bf90bc8d244b0c9cbe9
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index 00c4e96..3a6e2bb 100644
--- a/src/main/java/com/android/tools/r8/Version.java
+++ b/src/main/java/com/android/tools/r8/Version.java
@@ -13,7 +13,7 @@
 
   // This field is accessed from release scripts using simple pattern matching.
   // Therefore, changing this field could break our release scripts.
-  public static final String LABEL = "8.2.56";
+  public static final String LABEL = "8.2.57";
 
   private Version() {
   }
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/passes/NaturalIntLoopRemover.java b/src/main/java/com/android/tools/r8/ir/conversion/passes/NaturalIntLoopRemover.java
index a52a144..39f9e82 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/passes/NaturalIntLoopRemover.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/passes/NaturalIntLoopRemover.java
@@ -18,6 +18,7 @@
 import com.android.tools.r8.ir.conversion.passes.result.CodeRewriterResult;
 import com.android.tools.r8.ir.optimize.AffectedValues;
 import com.android.tools.r8.utils.WorkList;
+import com.google.common.collect.Sets;
 import java.util.Set;
 
 /**