[turbofan] Fix more -Wsign-compare warnings.

src/compiler/js-inlining-heuristic.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/js-inlining-heuristic.h"
 
 #include "src/compilation-info.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 #define TRACE(...)                                      \
   do {                                                  \
     if (FLAG_trace_turbo_inlining) PrintF(__VA_ARGS__); \
   } while (false)
 
 namespace {
 
 int CollectFunctions(Node* node, Handle<JSFunction>* functions,
                      int functions_size) {
-  DCHECK_NE(0u, functions_size);
+  DCHECK_NE(0, functions_size);
   HeapObjectMatcher m(node);
   if (m.HasValue() && m.Value()->IsJSFunction()) {
     functions[0] = Handle<JSFunction>::cast(m.Value());
     return 1;
   }
   if (m.IsPhi()) {
     int const value_input_count = m.node()->op()->ValueInputCount();
     if (value_input_count > functions_size) return 0;
     for (int n = 0; n < value_input_count; ++n) {
       HeapObjectMatcher m(node->InputAt(n));
@@ skipping 257 matching lines @@
   return jsgraph()->common();
 }
 
 SimplifiedOperatorBuilder* JSInliningHeuristic::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8