Minor, move lazyClosure out of TypeUtils.kt

core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.kt

@@ -144,27 +144,6 @@ fun <T> Collection<T>.closure(preserveOrder: Boolean = false, f: (T) -> Collecti
     return result
 }
 
-fun <T> Collection<T>.lazyClosure(f: (T) -> Collection<T>): Sequence<T> = sequence {
-    if (size == 0) return@sequence
-    var sizeBeforeIteration = 0
-
-    yieldAll(this@lazyClosure)
-    var yieldedCount = size
-    var elementsToCheck = this@lazyClosure
-
-    while (yieldedCount > sizeBeforeIteration) {
-        val toAdd = hashSetOf<T>()
-        elementsToCheck.forEach {
-            val neighbours = f(it)
-            yieldAll(neighbours)
-            yieldedCount += neighbours.size
-            toAdd.addAll(neighbours)
-        }
-        elementsToCheck = toAdd
-        sizeBeforeIteration = yieldedCount
-    }
-}
-
 fun boundClosure(types: Collection<KotlinType>): Collection<KotlinType> =
     types.closure { type -> TypeUtils.getTypeParameterDescriptorOrNull(type)?.upperBounds ?: emptySet() }