add ability to create child coroutine scope

GitOrigin-RevId: 4c2035e889b6380e2488f6eecff83b3ec50ac775

platform/util-ex/src/com/intellij/util/coroutineScope.kt

@@ -0,0 +1,23 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.util
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.job
+import org.jetbrains.annotations.ApiStatus.Experimental
+import org.jetbrains.annotations.ApiStatus.Internal
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
+
+@Internal
+@Experimental
+fun CoroutineScope.childScope(context: CoroutineContext = EmptyCoroutineContext, supervisor: Boolean = true): CoroutineScope {
+  require(context[Job] == null) {
+    "Found Job in context: $context"
+  }
+  val parentContext = coroutineContext
+  val parentJob = parentContext.job
+  val job = if (supervisor) SupervisorJob(parent = parentJob) else Job(parent = parentJob)
+  return CoroutineScope(parentContext + job + context)
+}