Remove obsolete BuiltInsInitializer

JvmBuiltIns do not use it for a long time already and work fine. It
seems that other implementations do not need it either

core/descriptors.jvm/src/org/jetbrains/kotlin/builtins/jvm/JvmBuiltInsSettings.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.builtins.jvm
 
-import org.jetbrains.kotlin.builtins.BuiltInsInitializer
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
@@ -500,13 +499,9 @@ private class FallbackBuiltIns private constructor() : KotlinBuiltIns(LockBasedS
     }
 
     companion object {
-        private val initializer = BuiltInsInitializer {
-            FallbackBuiltIns()
-        }
-
         @JvmStatic
-        val Instance: KotlinBuiltIns
-            get() = initializer.get()
+        val Instance: KotlinBuiltIns =
+            FallbackBuiltIns()
     }
 
     override fun getPlatformDependentDeclarationFilter() = PlatformDependentDeclarationFilter.All

core/descriptors/src/org/jetbrains/kotlin/builtins/BuiltInsInitializer.kt

@@ -1,66 +0,0 @@
-/*
- * Copyright 2010-2015 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.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.builtins
-
-import org.jetbrains.kotlin.utils.sure
-
-class BuiltInsInitializer<out T : KotlinBuiltIns>(
-        private val constructor: () -> T
-) {
-    @Volatile private var instance: T? = null
-
-    @Volatile private var initializing: Boolean = false
-
-    private var initializationFailed: Throwable? = null
-
-    @Synchronized private fun initialize() {
-        if (instance == null) {
-            if (initializationFailed != null) {
-                throw IllegalStateException(
-                        "Built-in library initialization failed previously: " + initializationFailed!!, initializationFailed)
-            }
-            if (initializing) {
-                throw IllegalStateException("Built-in library initialization loop")
-            }
-            initializing = true
-            try {
-                instance = constructor()
-            }
-            catch (e: Throwable) {
-                initializationFailed = e
-                throw IllegalStateException("Built-in library initialization failed. " + "Please ensure you have kotlin-stdlib.jar in the classpath: " + e, e)
-            }
-            finally {
-                initializing = false
-            }
-        }
-    }
-
-    fun get(): T {
-        if (initializing) {
-            synchronized (this) {
-                return instance.sure {
-                    "Built-ins are not initialized (note: We are under the same lock as initializing and instance)"
-                }
-            }
-        }
-        if (instance == null) {
-            initialize()
-        }
-        return instance!!
-    }
-}

core/descriptors/src/org/jetbrains/kotlin/builtins/DefaultBuiltIns.kt

@@ -24,12 +24,8 @@ class DefaultBuiltIns private constructor() : KotlinBuiltIns(LockBasedStorageMan
     }
 
     companion object {
-        private val initializer = BuiltInsInitializer {
-            DefaultBuiltIns()
-        }
-
         @JvmStatic
-        val Instance: DefaultBuiltIns
-            get() = initializer.get()
+        val Instance: DefaultBuiltIns =
+            DefaultBuiltIns()
     }
-}
+}