Do not initialize CoroutineExceptionHandler in Job <clinit> (Kotlin#2513)

* It slightly cuts down startup time
    * It simplifies the code in general
    * It do not serve its purpose, coroutines are already protected from StackOverflowError with nested event-loops where applicable

Author: qwwdfsad

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

@@ -113,16 +113,7 @@ public interface Job : CoroutineContext.Element {
     /**
      * Key for [Job] instance in the coroutine context.
      */
-    public companion object Key : CoroutineContext.Key<Job> {
-        init {
-            /*
-             * Here we make sure that CoroutineExceptionHandler is always initialized in advance, so
-             * that if a coroutine fails due to StackOverflowError we don't fail to report this error
-             * trying to initialize CoroutineExceptionHandler
-             */
-            CoroutineExceptionHandler
-        }
-    }
+    public companion object Key : CoroutineContext.Key<Job>
 
     // ------------ state query ------------