Reland VectorICs: ia32 store ics need a virtual register.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 10e9bb4e02ae94ff1dca623f52cd0fc574792fa4..433b9b8456dc869ad6774e166b0bb9f8509c9c03 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -990,6 +990,8 @@ class ExternalReference BASE_EMBEDDED {
   static ExternalReference invoke_function_callback(Isolate* isolate);
   static ExternalReference invoke_accessor_getter_callback(Isolate* isolate);
 
+  static ExternalReference vector_store_virtual_register(Isolate* isolate);
+
   Address address() const { return reinterpret_cast<Address>(address_); }
 
   // Used to check if single stepping is enabled in generated code.