CompileArrayPushCall should not use context register as a scratch.

src/x64/stub-cache-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 1470 matching lines @@
       __ bind(&attempt_to_grow_elements);
       if (!FLAG_inline_new) {
         __ jmp(&call_builtin);
       }
 
       __ movq(rdi, Operand(rsp, argc * kPointerSize));
       // Growing elements that are SMI-only requires special handling in case
       // the new element is non-Smi. For now, delegate to the builtin.
       Label no_fast_elements_check;
       __ JumpIfSmi(rdi, &no_fast_elements_check);
-      __ movq(rsi, FieldOperand(rdx, HeapObject::kMapOffset));
-      __ CheckFastObjectElements(rsi, &call_builtin, Label::kFar);
+      __ movq(rcx, FieldOperand(rdx, HeapObject::kMapOffset));
+      __ CheckFastObjectElements(rcx, &call_builtin, Label::kFar);
       __ bind(&no_fast_elements_check);
 
       ExternalReference new_space_allocation_top =
           ExternalReference::new_space_allocation_top_address(isolate());
       ExternalReference new_space_allocation_limit =
           ExternalReference::new_space_allocation_limit_address(isolate());
 
       const int kAllocationDelta = 4;
       // Load top.
       __ Load(rcx, new_space_allocation_top);
@@ skipping 2294 matching lines @@
   Handle<Code> ic_miss = masm->isolate()->builtins()->KeyedStoreIC_Miss();
   __ jmp(ic_miss, RelocInfo::CODE_TARGET);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64