FIR CFG: remove duplicating lambda enter -> exit connection

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraph.kt

@@ -68,6 +68,10 @@ sealed class CFGNode<out E : FirElement>(val owner: ControlFlowGraph, val level:
         internal fun addEdge(from: CFGNode<*>, to: CFGNode<*>, kind: EdgeKind, propagateDeadness: Boolean) {
             from._followingNodes += to
             to._previousNodes += from
+            addJustKindEdge(from, to, kind, propagateDeadness)
+        }
+
+        internal fun addJustKindEdge(from: CFGNode<*>, to: CFGNode<*>, kind: EdgeKind, propagateDeadness: Boolean) {
             if (kind != EdgeKind.Simple) {
                 from._outgoingEdges[to] = kind
                 to._incomingEdges[from] = kind

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraphBuilder.kt

@@ -166,7 +166,7 @@ class ControlFlowGraphBuilder {
             if (postponedExitNode != null) {
                 requireNotNull(postponedEnterNode)
                 val kind = if (postponedEnterNode.isDead) EdgeKind.Dead else EdgeKind.Cfg
-                CFGNode.addEdge(postponedEnterNode, postponedExitNode, kind, propagateDeadness = true)
+                CFGNode.addJustKindEdge(postponedEnterNode, postponedExitNode, kind, propagateDeadness = true)
             }
             lexicalScopes.pop()
         }