[turbofan] Rewrite ToObject as TurboFan stub.

src/full-codegen/s390/full-codegen-s390.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.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 919 matching lines @@
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
   Label convert, done_convert;
   __ JumpIfSmi(r2, &convert);
   __ CompareObjectType(r2, r3, r3, FIRST_JS_RECEIVER_TYPE);
   __ bge(&done_convert);
   __ CompareRoot(r2, Heap::kNullValueRootIndex);
   __ beq(&exit);
   __ CompareRoot(r2, Heap::kUndefinedValueRootIndex);
   __ beq(&exit);
   __ bind(&convert);
+  __ Push(cp);
   ToObjectStub stub(isolate());
   __ CallStub(&stub);
+  __ Pop(cp);
   __ bind(&done_convert);
   PrepareForBailoutForId(stmt->ToObjectId(), BailoutState::TOS_REGISTER);
   __ push(r2);
 
   // Check cache validity in generated code. If we cannot guarantee cache
   // validity, call the runtime system to check cache validity or get the
   // property names in a fixed array. Note: Proxies never have an enum cache,
   // so will always take the slow path.
   Label call_runtime;
   __ CheckEnumCache(&call_runtime);
@@ skipping 2737 matching lines @@
   DCHECK(kOSRBranchInstruction == br_instr);
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OnStackReplacement()->entry());
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_TARGET_ARCH_S390