Minor: make variables initialized in defineClass lateinit instead of nullable.

compiler/backend/src/org/jetbrains/kotlin/codegen/ClassNameCollectionClassBuilderFactory.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,7 +42,7 @@ abstract class ClassNameCollectionClassBuilderFactory(
 
         override fun getDelegate() = _delegate
 
-        private var classInternalName: String? = null
+        private lateinit var classInternalName: String
 
         override fun defineClass(origin: PsiElement?, version: Int, access: Int, name: String, signature: String?, superName: String, interfaces: Array<out String>) {
             classInternalName = name
@@ -50,9 +50,7 @@ abstract class ClassNameCollectionClassBuilderFactory(
         }
 
         override fun done() {
-            if (classInternalName != null) {
-                handleClashingNames(classInternalName!!, classCreatedFor)
-            }
+            handleClashingNames(classInternalName, classCreatedFor)
             super.done()
         }
     }

compiler/backend/src/org/jetbrains/kotlin/codegen/SignatureCollectingClassBuilderFactory.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -32,7 +32,7 @@ abstract class SignatureCollectingClassBuilderFactory(
 
     protected abstract fun handleClashingSignatures(data: ConflictingJvmDeclarationsData)
     protected abstract fun onClassDone(classOrigin: JvmDeclarationOrigin,
-                                       classInternalName: String?,
+                                       classInternalName: String,
                                        signatures: MultiMap<RawSignature, JvmDeclarationOrigin>)
 
     override fun newClassBuilder(origin: JvmDeclarationOrigin): DelegatingClassBuilder {
@@ -46,7 +46,7 @@ abstract class SignatureCollectingClassBuilderFactory(
 
         override fun getDelegate() = _delegate
 
-        private var classInternalName: String? = null
+        private lateinit var classInternalName: String
 
         private val signatures = LinkedMultiMap<RawSignature, JvmDeclarationOrigin>()
 

compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -91,7 +91,7 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
 
     override fun onClassDone(
             classOrigin: JvmDeclarationOrigin,
-            classInternalName: String?,
+            classInternalName: String,
             signatures: MultiMap<RawSignature, JvmDeclarationOrigin>
     ) {
         reportDiagnosticsTasks.add { reportClashingSignaturesInHierarchy(classOrigin, classInternalName, signatures) }
@@ -99,7 +99,7 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
 
     private fun reportClashingSignaturesInHierarchy(
             classOrigin: JvmDeclarationOrigin,
-            classInternalName: String?,
+            classInternalName: String,
             signatures: MultiMap<RawSignature, JvmDeclarationOrigin>
     ) {
         val descriptor = classOrigin.descriptor