Remove unused imports on 1.3 branch, this is the actual 1.3.49 version.

I will add the tag here.

R=christofferqa@google.com

Change-Id: I186093552b28313688c6214f87bfc6cd1d52270b
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/DexBuilder.java b/src/main/java/com/android/tools/r8/ir/conversion/DexBuilder.java
index ce17115..90981ac 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/DexBuilder.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/DexBuilder.java
@@ -3,8 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 package com.android.tools.r8.ir.conversion;
 
-import com.android.tools.r8.code.Const4;
-import com.android.tools.r8.code.ConstWide16;
 import com.android.tools.r8.code.FillArrayData;
 import com.android.tools.r8.code.FillArrayDataPayload;
 import com.android.tools.r8.code.Format31t;
@@ -36,7 +34,6 @@
 import com.android.tools.r8.code.MoveWideFrom16;
 import com.android.tools.r8.code.Nop;
 import com.android.tools.r8.code.ReturnVoid;
-import com.android.tools.r8.code.ReturnWide;
 import com.android.tools.r8.code.Throw;
 import com.android.tools.r8.dex.Constants;
 import com.android.tools.r8.errors.Unreachable;