Use weak cells to embed maps in store handler.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 38884aa65bc2924f50a8f076d9d6553e9104d72d..ba4e308e5fec4c296a0324b38c4c9db6489b90b1 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -5128,18 +5128,6 @@ void MacroAssembler::CheckPageFlag(
 }
 
 
-void MacroAssembler::CheckMapDeprecated(Handle<Map> map,
-                                        Register scratch,
-                                        Label* if_deprecated) {
-  if (map->CanBeDeprecated()) {
-    Move(scratch, map);
-    movl(scratch, FieldOperand(scratch, Map::kBitField3Offset));
-    andl(scratch, Immediate(Map::Deprecated::kMask));
-    j(not_zero, if_deprecated);
-  }
-}
-
-
 void MacroAssembler::JumpIfBlack(Register object,
                                  Register bitmap_scratch,
                                  Register mask_scratch,