Reland r20974: Unify and simplify the FastCloneShallowArrayStub

src/mips/full-codegen-mips.cc

Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index c51f9bc038a61e75ef10329e18d6cf132519a090..13032ca75f8f74670813e54ca19dfdf3301d1091 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -1805,33 +1805,12 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   __ lw(a3, FieldMemOperand(a3, JSFunction::kLiteralsOffset));
   __ li(a2, Operand(Smi::FromInt(expr->literal_index())));
   __ li(a1, Operand(constant_elements));
-  if (has_fast_elements && constant_elements_values->map() ==
-      isolate()->heap()->fixed_cow_array_map()) {
-    FastCloneShallowArrayStub stub(
-        isolate(),
-        FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS,
-        allocation_site_mode,
-        length);
-    __ CallStub(&stub);
-    __ IncrementCounter(isolate()->counters()->cow_arrays_created_stub(),
-        1, a1, a2);
-  } else if (expr->depth() > 1 || Serializer::enabled(isolate()) ||
-             length > FastCloneShallowArrayStub::kMaximumClonedLength) {
+  if (expr->depth() > 1) {
     __ li(a0, Operand(Smi::FromInt(flags)));
     __ Push(a3, a2, a1, a0);
     __ CallRuntime(Runtime::kHiddenCreateArrayLiteral, 4);
   } else {
-    ASSERT(IsFastSmiOrObjectElementsKind(constant_elements_kind) ||
-           FLAG_smi_only_arrays);
-    FastCloneShallowArrayStub::Mode mode =
-        FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS;
-
-    if (has_fast_elements) {
-      mode = FastCloneShallowArrayStub::CLONE_ELEMENTS;
-    }
-
-    FastCloneShallowArrayStub stub(isolate(), mode, allocation_site_mode,
-                                   length);
+    FastCloneShallowArrayStub stub(isolate(), allocation_site_mode);
     __ CallStub(&stub);
   }