Remove const field 'initMethodName' in class com.android.tools.r8.graph.DexItemFactory

This is a duplication of another field 'constructorMethodName'.

Change-Id: Ib9a949ff43eafbd86541233053a76a1463323275
diff --git a/AUTHORS b/AUTHORS
index d4aa190..9087735 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -5,3 +5,4 @@
 
 Google Inc.
 Uber Technologies Inc.
+Albert Jin <albert.jin@gmail.com>
diff --git a/src/main/java/com/android/tools/r8/graph/DexItemFactory.java b/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
index 963d503..0d1a5bc 100644
--- a/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
+++ b/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
@@ -116,8 +116,6 @@
   public final DexString boxedShortDescriptor = createString("Ljava/lang/Short;");
   public final DexString boxedNumberDescriptor = createString("Ljava/lang/Number;");
 
-  public final DexString initMethodName = createString("<init>");
-
   public final DexString unboxBooleanMethodName = createString("booleanValue");
   public final DexString unboxByteMethodName = createString("byteValue");
   public final DexString unboxCharMethodName = createString("charValue");
@@ -517,7 +515,12 @@
     public final DexMethod init;
 
     private NullPointerExceptionMethods() {
-      init = createMethod(npeDescriptor, initMethodName, voidDescriptor, DexString.EMPTY_ARRAY);
+      init =
+          createMethod(
+              npeDescriptor,
+              constructorMethodName,
+              voidDescriptor,
+              DexString.EMPTY_ARRAY);
     }
   }
 
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/UnusedArgumentsCollector.java b/src/main/java/com/android/tools/r8/ir/optimize/UnusedArgumentsCollector.java
index 1a71b05..9ffff5c 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/UnusedArgumentsCollector.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/UnusedArgumentsCollector.java
@@ -161,7 +161,7 @@
       do {
         if (newName == null) {
           newName = method.method.name;
-        } else if (method.method.name != appView.dexItemFactory().initMethodName) {
+        } else if (!appView.dexItemFactory().isConstructor(method.method)) {
           newName =
               appView.dexItemFactory().createString(method.method.name.toSourceString() + count);
         } else {