[turbofan] Fix write barrier handling of map values.

src/compiler/x64/code-generator-x64.cc

 // Copyright 2013 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/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 191 matching lines @@
         operand_(operand),
         value_(value),
         scratch0_(scratch0),
         scratch1_(scratch1),
         mode_(mode) {}
 
   void Generate() final {
     if (mode_ > RecordWriteMode::kValueIsPointer) {
       __ JumpIfSmi(value_, exit());
     }
-    if (mode_ > RecordWriteMode::kValueIsMap) {
-      __ CheckPageFlag(value_, scratch0_,
-                       MemoryChunk::kPointersToHereAreInterestingMask, zero,
-                       exit());
-    }
+    __ CheckPageFlag(value_, scratch0_,
+                     MemoryChunk::kPointersToHereAreInterestingMask, zero,
+                     exit());
     SaveFPRegsMode const save_fp_mode =
         frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
     RecordWriteStub stub(isolate(), object_, scratch0_, scratch1_,
                          EMIT_REMEMBERED_SET, save_fp_mode);
     __ leap(scratch1_, operand_);
     __ CallStub(&stub);
   }
 
  private:
   Register const object_;
@@ skipping 1937 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8