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

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index ff8d4be1925914672434f2b873db1924b7b1693b..7000e1ddc2f4df9ab918e3e2c5e24fcb5e42d21c 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -1734,20 +1734,15 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) {
   __ 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)