[turbofan] Fix -Wsign-compare warnings.

src/compiler/effect-control-linearizer.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/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 78 matching lines @@
 void UpdateBlockControl(BasicBlock* block,
                         BlockEffectControlMap* block_effects) {
   Node* control = block->NodeAt(0);
   DCHECK(NodeProperties::IsControl(control));
 
   // Do not rewire the end node.
   if (control->opcode() == IrOpcode::kEnd) return;
 
   // Update all inputs to the given control node with the correct control.
   DCHECK(control->opcode() == IrOpcode::kMerge ||
-         control->op()->ControlInputCount() == block->PredecessorCount());
-  if (control->op()->ControlInputCount() != block->PredecessorCount()) {
+         static_cast<size_t>(control->op()->ControlInputCount()) ==
+             block->PredecessorCount());
+  if (static_cast<size_t>(control->op()->ControlInputCount()) !=
+      block->PredecessorCount()) {
     return;  // We already re-wired the control inputs of this node.
   }
   for (int i = 0; i < control->op()->ControlInputCount(); i++) {
     Node* input = NodeProperties::GetControlInput(control, i);
     BasicBlock* predecessor = block->PredecessorAt(static_cast<size_t>(i));
     const BlockEffectControlData& block_effect =
         block_effects->For(predecessor, block);
     if (input != block_effect.current_control) {
       NodeProperties::ReplaceControlInput(control, block_effect.current_control,
                                           i);
@@ skipping 3536 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kEliminatable);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8