[turbofan] optimize spills in defered blocks

src/compiler/live-range-separator.cc

 // 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/live-range-separator.h"
 #include "src/compiler/register-allocator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 101 matching lines @@
     }
     int first_instr = range->first_interval()->FirstGapIndex();
     if (!data()->code()->GetInstructionBlock(first_instr)->IsDeferred()) {
       SplinterLiveRange(range, data());
     }
   }
 }
 
 
 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()) {
       continue;
     }
 
     LiveRange *child = top;
     for (; child != nullptr; child = child->next()) {
       if (child->spilled() ||
           child->NextSlotPosition(child->Start()) != nullptr) {
         break;
       }
     }
-    if (child == nullptr) top->MarkSpilledInDeferredBlock();
+    if (child == nullptr) {
+      top->TreatAsSpilledInDeferredBlock(data()->allocation_zone(),
+                                         code->InstructionBlockCount());
+    }
   }
 }
 
 
 void LiveRangeMerger::Merge() {
   MarkRangesSpilledInDeferredBlocks();
 
   int live_range_count = static_cast<int>(data()->live_ranges().size());
   for (int i = 0; i < live_range_count; ++i) {
     TopLevelLiveRange *range = data()->live_ranges()[i];
     if (range == nullptr || range->IsEmpty() || !range->IsSplinter()) {
       continue;
     }
     TopLevelLiveRange *splinter_parent = range->splintered_from();
 
     int to_remove = range->vreg();
     splinter_parent->Merge(range, data()->allocation_zone());
     data()->live_ranges()[to_remove] = nullptr;
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8