Fix for KT-13695, KT-13159 J2K: Invalid conversion context setup for plain text pastes

Extending, Implementing, imports from paste target file previously not implemented

core/util.runtime/src/org/jetbrains/kotlin/utils/addToStdlib.kt

@@ -121,3 +121,7 @@ inline fun <T> Iterable<T>.sumByLong(selector: (T) -> Long): Long {
     }
     return sum
 }
+
+inline fun <T, C : Collection<T>, O> C.ifNotEmpty(body: C.() -> O?): O? = if (isNotEmpty()) this.body() else null
+
+inline fun <T, O> Array<out T>.ifNotEmpty(body: Array<out T>.() -> O?): O? = if (isNotEmpty()) this.body() else null