MIPS: Update the gap resolver to support Smi constants.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 05fa79247e5fa6722fbe49f294c7a4ec10ca40ca..9c6bb04f4d673cbaa3c5afaed811ef6bf5535b8d 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -521,6 +521,12 @@ int LCodeGen::ToInteger32(LConstantOperand* op) const {
 }
 
 
+Smi* LCodeGen::ToSmi(LConstantOperand* op) const {
+  HConstant* constant = chunk_->LookupConstant(op);
+  return Smi::FromInt(constant->Integer32Value());
+}
+
+
 double LCodeGen::ToDouble(LConstantOperand* op) const {
   HConstant* constant = chunk_->LookupConstant(op);
   ASSERT(constant->HasDoubleValue());