[stubs] Add option to allow LO space allocation

src/code-stub-assembler.cc

 // Copyright 2016 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/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 765 matching lines @@
                                               Node* top_address,
                                               Node* limit_address) {
   Node* top = Load(MachineType::Pointer(), top_address);
   Node* limit = Load(MachineType::Pointer(), limit_address);
 
   // If there's not enough space, call the runtime.
   Variable result(this, MachineRepresentation::kTagged);
   Label runtime_call(this, Label::kDeferred), no_runtime_call(this);
   Label merge_runtime(this, &result);
 
+  if (flags & kAllowLargeObjectAllocation) {
+    Label next(this);
+    GotoIf(IsRegularHeapObjectSize(size_in_bytes), &next);
+
+    Node* runtime_flags = SmiConstant(
+        Smi::FromInt(AllocateDoubleAlignFlag::encode(false) |
+                     AllocateTargetSpace::encode(AllocationSpace::LO_SPACE)));
+    Node* const runtime_result =
+        CallRuntime(Runtime::kAllocateInTargetSpace, NoContextConstant(),
+                    SmiTag(size_in_bytes), runtime_flags);
+    result.Bind(runtime_result);
+    Goto(&merge_runtime);
+
+    Bind(&next);
+  }
+
   Node* new_top = IntPtrAdd(top, size_in_bytes);
   Branch(UintPtrGreaterThanOrEqual(new_top, limit), &runtime_call,
          &no_runtime_call);
 
   Bind(&runtime_call);
   Node* runtime_result;
   if (flags & kPretenured) {
     Node* runtime_flags = SmiConstant(
         Smi::FromInt(AllocateDoubleAlignFlag::encode(false) |
                      AllocateTargetSpace::encode(AllocationSpace::OLD_SPACE)));
@@ skipping 7410 matching lines @@
 
 Node* CodeStubAssembler::IsDebugActive() {
   Node* is_debug_active = Load(
       MachineType::Uint8(),
       ExternalConstant(ExternalReference::debug_is_active_address(isolate())));
   return WordNotEqual(is_debug_active, Int32Constant(0));
 }
 
 }  // namespace internal
 }  // namespace v8