[turbofan] Preprocessing live ranges before register allocation.

src/compiler/preprocess-live-ranges.cc

Index: src/compiler/preprocess-live-ranges.cc
diff --git a/src/compiler/preprocess-live-ranges.cc b/src/compiler/preprocess-live-ranges.cc
new file mode 100644
index 0000000000000000000000000000000000000000..81283a898a0f778658dc4b74a980556fb1e5d418
--- /dev/null
+++ b/src/compiler/preprocess-live-ranges.cc
@@ -0,0 +1,29 @@
+// 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/preprocess-live-ranges.h"
+#include "src/compiler/register-allocator.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+
+#define TRACE(...)                             \
+  do {                                         \
+    if (FLAG_trace_alloc) PrintF(__VA_ARGS__); \
+  } while (false)
+
+
+void PreprocessLiveRanges::PreprocessRanges() {
+  SplitRangesAroundDeferredBlocks();
+}
+
+
+void PreprocessLiveRanges::SplitRangesAroundDeferredBlocks() {}
+
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8