[turbofan] optimize spills in defered blocks

src/compiler/live-range-separator.cc

Index: src/compiler/live-range-separator.cc
diff --git a/src/compiler/live-range-separator.cc b/src/compiler/live-range-separator.cc
index 932e9d59c5d23162e4bae6c75dd23cfbc832847c..e3cd0a3137deea497aefa22c14b883a99b4c830c 100644
--- a/src/compiler/live-range-separator.cc
+++ b/src/compiler/live-range-separator.cc
@@ -119,6 +119,7 @@ void LiveRangeSeparator::Splinter() {
 
 
 void LiveRangeMerger::MarkRangesSpilledInDeferredBlocks() {
+  const InstructionSequence *code = data()->code();
   for (TopLevelLiveRange *top : data()->live_ranges()) {
     if (top == nullptr || top->IsEmpty() || top->splinter() == nullptr ||
         top->HasSpillOperand() || !top->splinter()->HasSpillRange()) {
@@ -132,7 +133,10 @@ void LiveRangeMerger::MarkRangesSpilledInDeferredBlocks() {
         break;
       }
     }
-    if (child == nullptr) top->MarkSpilledInDeferredBlock();
+    if (child == nullptr) {
+      top->TreatAsSpilledInDeferredBlock(data()->allocation_zone(),
+                                         code->InstructionBlockCount());
+    }
   }
 }