Refactor platform-specific code for determining shared stub for keyed load/stores.

src/arm/stub-cache-arm.cc

Index: src/arm/stub-cache-arm.cc
diff --git a/src/arm/stub-cache-arm.cc b/src/arm/stub-cache-arm.cc
index 7fd5fa71f385c8247ded2038ccef31e6748c768b..7b652d30f58fbde0da9b53b37f7822031923f184 100644
--- a/src/arm/stub-cache-arm.cc
+++ b/src/arm/stub-cache-arm.cc
@@ -3121,15 +3121,8 @@ MaybeObject* KeyedLoadStubCompiler::CompileLoadElement(Map* receiver_map) {
   //  -- r0    : key
   //  -- r1    : receiver
   // -----------------------------------
-  MaybeObject* maybe_stub;
-  if (receiver_map->has_fast_elements()) {
-    maybe_stub = KeyedLoadFastElementStub().TryGetCode();
-  } else {
-    ASSERT(receiver_map->has_external_array_elements());
-    JSObject::ElementsKind elements_kind = receiver_map->elements_kind();
-    maybe_stub = KeyedLoadExternalArrayStub(elements_kind).TryGetCode();
-  }
   Code* stub;
+  MaybeObject* maybe_stub = ComputeSharedKeyedLoadElementStub(receiver_map);
   if (!maybe_stub->To(&stub)) return maybe_stub;
   __ DispatchMap(r1,
                  r2,
@@ -3213,8 +3206,7 @@ MaybeObject* KeyedStoreStubCompiler::CompileStoreField(JSObject* object,
 }
 
 
-MaybeObject* KeyedStoreStubCompiler::CompileStoreElement(
-    Map* receiver_map) {
+MaybeObject* KeyedStoreStubCompiler::CompileStoreElement(Map* receiver_map) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
@@ -3222,16 +3214,8 @@ MaybeObject* KeyedStoreStubCompiler::CompileStoreElement(
   //  -- lr    : return address
   //  -- r3    : scratch
   // -----------------------------------
-  MaybeObject* maybe_stub;
-  if (receiver_map->has_fast_elements()) {
-    bool is_js_array = receiver_map->instance_type() == JS_ARRAY_TYPE;
-    maybe_stub = KeyedStoreFastElementStub(is_js_array).TryGetCode();
-  } else {
-    ASSERT(receiver_map->has_external_array_elements());
-    JSObject::ElementsKind elements_kind = receiver_map->elements_kind();
-    maybe_stub = KeyedStoreExternalArrayStub(elements_kind).TryGetCode();
-  }
   Code* stub;
+  MaybeObject* maybe_stub = ComputeSharedKeyedStoreElementStub(receiver_map);
   if (!maybe_stub->To(&stub)) return maybe_stub;
   __ DispatchMap(r2,
                  r3,