[turbofan] Fix -Wsign-compare warnings.

src/compiler/escape-analysis.cc

 // Copyright 2015 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/escape-analysis.h"
 
 #include <limits>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 402 matching lines @@
     Node* input2 = NodeProperties::GetValueInput(node2, i);
     if (!IsEquivalentPhi(input1, input2)) {
       return false;
     }
   }
   return true;
 }
 
 bool IsEquivalentPhi(Node* phi, ZoneVector<Node*>& inputs) {
   if (phi->opcode() != IrOpcode::kPhi) return false;
-  if (phi->op()->ValueInputCount() != inputs.size()) {
+  if (static_cast<size_t>(phi->op()->ValueInputCount()) != inputs.size()) {
     return false;
   }
   for (size_t i = 0; i < inputs.size(); ++i) {
     Node* input = NodeProperties::GetValueInput(phi, static_cast<int>(i));
     if (!IsEquivalentPhi(input, inputs[i])) {
       return false;
     }
   }
   return true;
 }
@@ skipping 40 matching lines @@
                               CommonOperatorBuilder* common) {
   DCHECK(at->opcode() == IrOpcode::kEffectPhi ||
          at->opcode() == IrOpcode::kPhi);
   bool changed = false;
   for (size_t i = 0; i < field_count(); ++i) {
     if (Node* field = cache->GetFields(i)) {
       changed = changed || GetField(i) != field;
       SetField(i, field);
       TRACE("    Field %zu agree on rep #%d\n", i, field->id());
     } else {
-      int arity = at->opcode() == IrOpcode::kEffectPhi
-                      ? at->op()->EffectInputCount()
-                      : at->op()->ValueInputCount();
+      size_t arity = at->opcode() == IrOpcode::kEffectPhi
+                         ? at->op()->EffectInputCount()
+                         : at->op()->ValueInputCount();
       if (cache->fields().size() == arity) {
         changed = MergeFields(i, at, cache, graph, common) || changed;
       } else {
         if (GetField(i) != nullptr) {
           TRACE("    Field %zu cleared\n", i);
           changed = true;
         }
         SetField(i, nullptr);
       }
     }
@@ skipping 1185 matching lines @@
     }
   }
   return false;
 }
 
 Graph* EscapeAnalysis::graph() const { return status_analysis_->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8