[turbofan] Cache float32 constants on the JSGraph level.

src/compiler/common-node-cache.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/common-node-cache.h"
+
+#include "src/assembler.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+Node** CommonNodeCache::FindExternalConstant(ExternalReference value) {
+  return external_constants_.Find(zone(), bit_cast<intptr_t>(value.address()));
+}
+
+
+void CommonNodeCache::GetCachedNodes(ZoneVector<Node*>* nodes) {
+  int32_constants_.GetCachedNodes(nodes);
+  int64_constants_.GetCachedNodes(nodes);
+  float32_constants_.GetCachedNodes(nodes);
+  float64_constants_.GetCachedNodes(nodes);
+  external_constants_.GetCachedNodes(nodes);
+  number_constants_.GetCachedNodes(nodes);
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8