Use direct loop when filling small arrays.

src/ia32/assembler-ia32.cc

Index: src/ia32/assembler-ia32.cc
diff --git a/src/ia32/assembler-ia32.cc b/src/ia32/assembler-ia32.cc
index 26e40b15bc3cbc02f3fb85af8c5b53409b0d3d71..a5be634df7c2b38ca2727f2f2ba35dc0962b302e 100644
--- a/src/ia32/assembler-ia32.cc
+++ b/src/ia32/assembler-ia32.cc
@@ -776,6 +776,13 @@ void Assembler::rep_stos() {
 }
 
 
+void Assembler::stos() {
+  EnsureSpace ensure_space(this);
+  last_pc_ = pc_;
+  EMIT(0xAB);
+}
+
+
 void Assembler::xchg(Register dst, Register src) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;