[turbofan] Add early detection of object state cycles.

src/compiler/escape-analysis-reducer.cc

Index: src/compiler/escape-analysis-reducer.cc
diff --git a/src/compiler/escape-analysis-reducer.cc b/src/compiler/escape-analysis-reducer.cc
index c69b86c488ddfb7ccb7016f0d6ac984be28e4ffe..a2b53c0b875b5b54e9feac606e3939cab6f9226a 100644
--- a/src/compiler/escape-analysis-reducer.cc
+++ b/src/compiler/escape-analysis-reducer.cc
@@ -305,6 +305,11 @@ Node* EscapeAnalysisReducer::ReduceStateValueInput(Node* node, int node_index,
   if (input->opcode() == IrOpcode::kFinishRegion ||
       input->opcode() == IrOpcode::kAllocate) {
     if (escape_analysis()->IsVirtual(input)) {
+      if (escape_analysis()->IsCyclicObjectState(effect, input)) {
+        // TODO(mstarzinger): Represent cyclic object states differently to
+        // ensure the scheduler can properly handle such object states.
+        FATAL("Cyclic object state detected by escape analysis.");
+      }
       if (Node* object_state =
               escape_analysis()->GetOrCreateObjectState(effect, input)) {
         if (node_multiused || (multiple_users && !already_cloned)) {