Turn StoreIC::Megamorphic into a builtin, get rid of the non-monomorphic-cache

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index 7173e54504aab9cccc653e4321a6527544d92aa5..5456cd5b4f3b277811ac5de80078def8b745d47a 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -4667,6 +4667,14 @@ static void Generate_StoreIC_Setter_ForDeopt(MacroAssembler* masm) {
   NamedStoreHandlerCompiler::GenerateStoreViaSetterForDeopt(masm);
 }
 
+static void Generate_StoreIC_Megamorphic(MacroAssembler* masm) {
+  StoreIC::GenerateMegamorphic(masm);
+}
+
+static void Generate_StoreIC_Megamorphic_Strict(MacroAssembler* masm) {
+  StoreIC::GenerateMegamorphic(masm);
+}
+
 
 static void Generate_KeyedStoreIC_Megamorphic(MacroAssembler* masm) {
   KeyedStoreIC::GenerateMegamorphic(masm, SLOPPY);