Clarify exception recovery documentation regarding suppressed exceptions (#2544)

Fixes KT-44478

Author: qwwdfsad

docs/topics/debugging.md

@@ -46,6 +46,10 @@ It is easy to demonstrate with actual stacktraces of the same program that await
 
 The only downside of this approach is losing referential transparency of the exception. 
 
+> Note that suppressed exceptions are not copied and are left intact in the cause
+> in order to prevent cycles in the exceptions chain, obscure`[CIRCULAR REFERENCE]` messages
+> and even [crashes](https://jira.qos.ch/browse/LOGBACK-1027) in some frameworks
+
 ### Stacktrace recovery machinery   
 
 This section explains the inner mechanism of stacktrace recovery and can be skipped.

kotlinx-coroutines-core/common/src/Debug.common.kt

@@ -35,6 +35,7 @@ public interface CopyableThrowable<T> where T : Throwable, T : CopyableThrowable
      * For better debuggability, it is recommended to use original exception as [cause][Throwable.cause] of the resulting one.
      * Stacktrace of copied exception will be overwritten by stacktrace recovery machinery by [Throwable.setStackTrace] call.
      * An exception can opt-out of copying by returning `null` from this function.
+     * Suppressed exceptions of the original exception should not be copied in order to avoid circular exceptions.
      */
     public fun createCopy(): T?
 }