[wasm] Break a cycle with a loop node in the int64-lowering.

src/compiler/int64-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/int64-lowering.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 43 matching lines @@
       LowerNode(top.node);
     } else {
       // Push the next input onto the stack.
       Node* input = top.node->InputAt(top.input_index++);
       if (state_.Get(input) == State::kUnvisited) {
         if (input->opcode() == IrOpcode::kPhi) {
           // To break cycles with phi nodes we push phis on a separate stack so
           // that they are processed after all other nodes.
           PreparePhiReplacement(input);
           stack_.push_front({input, 0});
-        } else if (input->opcode() == IrOpcode::kEffectPhi) {
+        } else if (input->opcode() == IrOpcode::kEffectPhi ||
+                   input->opcode() == IrOpcode::kLoop) {
           stack_.push_front({input, 0});
         } else {
           stack_.push_back({input, 0});
         }
         state_.Set(input, State::kOnStack);
       }
     }
   }
 }
 
@@ skipping 813 matching lines @@
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_low, false),
                 graph()->NewNode(
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_high, false));
   }
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8