Merge r10380, r10381 from the bleeding_edge to the 3.7 branch.

src/x64/code-stubs-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4031 matching lines @@
   //   rax is object map.
   //   rdx is function.
   //   rbx is function prototype.
   if (!HasCallSiteInlineCheck()) {
     __ StoreRoot(rdx, Heap::kInstanceofCacheFunctionRootIndex);
     __ StoreRoot(rax, Heap::kInstanceofCacheMapRootIndex);
   } else {
     // Get return address and delta to inlined map check.
     __ movq(kScratchRegister, Operand(rsp, 0 * kPointerSize));
     __ subq(kScratchRegister, Operand(rsp, 1 * kPointerSize));
-    __ movq(Operand(kScratchRegister, kOffsetToMapCheckValue), rax);
     if (FLAG_debug_code) {
       __ movl(rdi, Immediate(kWordBeforeMapCheckValue));
       __ cmpl(Operand(kScratchRegister, kOffsetToMapCheckValue - 4), rdi);
       __ Assert(equal, "InstanceofStub unexpected call site cache (check).");
     }
+    __ movq(kScratchRegister,
+            Operand(kScratchRegister, kOffsetToMapCheckValue));
+    __ movq(Operand(kScratchRegister, 0), rax);
   }
 
   __ movq(rcx, FieldOperand(rax, Map::kPrototypeOffset));
 
   // Loop through the prototype chain looking for the function prototype.
   Label loop, is_instance, is_not_instance;
   __ LoadRoot(kScratchRegister, Heap::kNullValueRootIndex);
   __ bind(&loop);
   __ cmpq(rcx, rbx);
   __ j(equal, &is_instance, Label::kNear);
@@ skipping 2025 matching lines @@
                                  xmm0,
                                  &slow_elements);
   __ ret(0);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64