Temporarily remove isInitialized and tests, but keep the implementation

This is needed because we want the compiler code to stay as much the
same in master and in 1.2 as possible

libraries/stdlib/src/kotlin/internal/Annotations.kt

@@ -65,12 +65,3 @@ internal annotation class InlineOnly
 @Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY)
 @Retention(AnnotationRetention.BINARY)
 internal annotation class DynamicExtension
-
-/**
- * The value of this parameter should be a property reference expression (`this::foo`), referencing a `lateinit` property,
- * the backing field of which is accessible at the point where the corresponding argument is passed.
- */
-@Target(AnnotationTarget.VALUE_PARAMETER)
-@Retention(AnnotationRetention.BINARY)
-@SinceKotlin("1.2")
-internal annotation class AccessibleLateinitPropertyLiteral

libraries/stdlib/src/kotlin/util/Lateinit.kt

@@ -1,19 +0,0 @@
-@file:kotlin.jvm.JvmName("LateinitKt")
-@file:kotlin.jvm.JvmVersion
-@file:Suppress("unused")
-
-package kotlin
-
-import kotlin.internal.InlineOnly
-import kotlin.internal.AccessibleLateinitPropertyLiteral
-import kotlin.reflect.KProperty0
-
-/**
- * Returns `true` if this lateinit property has been assigned a value, and `false` otherwise.
- *
- * Cannot be used in an inline function, to avoid binary compatibility issues.
- */
-@SinceKotlin("1.2")
-@InlineOnly
-inline val @receiver:AccessibleLateinitPropertyLiteral KProperty0<*>.isInitialized: Boolean
-    get() = throw NotImplementedError("Implementation is intrinsic")