[runtime] Replace the EQUALS builtin with proper Object::Equals.

src/x64/code-stubs-x64.cc

 // Copyright 2013 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_X64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 1716 matching lines @@
     __ ret(0);
   }
   __ bind(&runtime_call);
 
   // Push arguments below the return address to prepare jump to builtin.
   __ PopReturnAddressTo(rcx);
   __ Push(rdx);
   __ Push(rax);
 
   // Figure out which native to call and setup the arguments.
-  if (cc == equal && strict()) {
+  if (cc == equal) {
     __ PushReturnAddressFrom(rcx);
-    __ TailCallRuntime(Runtime::kStrictEquals, 2, 1);
+    __ TailCallRuntime(strict() ? Runtime::kStrictEquals : Runtime::kEquals, 2,
+                       1);
   } else {
-    int context_index;
-    if (cc == equal) {
-      context_index = Context::EQUALS_BUILTIN_INDEX;
-    } else {
-      context_index = is_strong(strength())
-                          ? Context::COMPARE_STRONG_BUILTIN_INDEX
-                          : Context::COMPARE_BUILTIN_INDEX;
-      __ Push(Smi::FromInt(NegativeComparisonResult(cc)));
-    }
-
+    int context_index = is_strong(strength())
+                            ? Context::COMPARE_STRONG_BUILTIN_INDEX
+                            : Context::COMPARE_BUILTIN_INDEX;
+    __ Push(Smi::FromInt(NegativeComparisonResult(cc)));
     __ PushReturnAddressFrom(rcx);
 
     // Call the native; it returns -1 (less), 0 (equal), or 1 (greater)
     // tagged as a small integer.
     __ InvokeBuiltin(context_index, JUMP_FUNCTION);
   }
 
   __ bind(&miss);
   GenerateMiss(masm);
 }
@@ skipping 3822 matching lines @@
                            kStackSpace, nullptr, return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64