Reland 'Do not embed constant functions in StoreTransition stub.'

src/ic/x64/handler-compiler-x64.cc

Index: src/ic/x64/handler-compiler-x64.cc
diff --git a/src/ic/x64/handler-compiler-x64.cc b/src/ic/x64/handler-compiler-x64.cc
index 2e19fb5abab47a437d8d9a0a8eeadb760cfd20a0..dfbadcce1175f0014e661ab4db42f860ea82dd4f 100644
--- a/src/ic/x64/handler-compiler-x64.cc
+++ b/src/ic/x64/handler-compiler-x64.cc
@@ -335,10 +335,19 @@ void NamedStoreHandlerCompiler::GenerateRestoreMap(Handle<Map> transition,
   }
 }
 
-void NamedStoreHandlerCompiler::GenerateConstantCheck(Object* constant,
+
+void NamedStoreHandlerCompiler::GenerateConstantCheck(Register map_reg,
+                                                      int descriptor,
                                                       Register value_reg,
+                                                      Register scratch,
                                                       Label* miss_label) {
-  __ Cmp(value_reg, handle(constant, isolate()));
+  DCHECK(!map_reg.is(scratch));
+  DCHECK(!map_reg.is(value_reg));
+  DCHECK(!value_reg.is(scratch));
+  __ LoadInstanceDescriptors(map_reg, scratch);
+  __ movp(scratch,
+          FieldOperand(scratch, DescriptorArray::GetValueOffset(descriptor)));
+  __ cmpp(value_reg, scratch);
   __ j(not_equal, miss_label);
 }