[turbofan] Use appropriate type for NodeId.

src/compiler/node.h

 // Copyright 2013 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.
 
 #ifndef V8_COMPILER_NODE_H_
 #define V8_COMPILER_NODE_H_
 
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/types-inl.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 class Edge;
 class Graph;
 
 
 // Marks are used during traversal of the graph to distinguish states of nodes.
 // Each node has a mark which is a monotonically increasing integer, and a
 // {NodeMarker} has a range of values that indicate states of a node.
 typedef uint32_t Mark;
 
 
 // NodeIds are identifying numbers for nodes that can be used to index auxiliary
 // out-of-line data associated with each node.
-typedef int32_t NodeId;
+typedef uint32_t NodeId;
 
 
 // A Node is the basic primitive of graphs. Nodes are chained together by
 // input/use chains but by default otherwise contain only an identifying number
 // which specific applications of graphs and nodes can use to index auxiliary
 // out-of-line data, especially transient data.
 //
 // In addition Nodes only contain a mutable Operator that may change during
 // compilation, e.g. during lowering passes. Other information that needs to be
 // associated with Nodes during compilation must be stored out-of-line indexed
@@ skipping 510 matching lines @@
 }
 
 
 Node::Uses::const_iterator Node::Uses::end() const { return const_iterator(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_NODE_H_