[turbofan] Deferred blocks splintering.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 4c9241fd805531bb73bcdb6fe686bdfef472038d..16a5ceda74ef9bcfbd5e9dba9bcd704efc445e59 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -780,6 +780,8 @@ source_set("v8_base") {
     "src/compiler/jump-threading.h",
     "src/compiler/linkage.cc",
     "src/compiler/linkage.h",
+    "src/compiler/live-range-separator.cc",
+    "src/compiler/live-range-separator.h",
     "src/compiler/liveness-analyzer.cc",
     "src/compiler/liveness-analyzer.h",
     "src/compiler/load-elimination.cc",
@@ -818,8 +820,6 @@ source_set("v8_base") {
     "src/compiler/pipeline.h",
     "src/compiler/pipeline-statistics.cc",
     "src/compiler/pipeline-statistics.h",
-    "src/compiler/preprocess-live-ranges.cc",
-    "src/compiler/preprocess-live-ranges.h",
     "src/compiler/raw-machine-assembler.cc",
     "src/compiler/raw-machine-assembler.h",
     "src/compiler/register-allocator.cc",