Implemented one-char cache lookup in generated code.

src/mips/codegen-mips.cc

Index: src/mips/codegen-mips.cc
diff --git a/src/mips/codegen-mips.cc b/src/mips/codegen-mips.cc
index 1446ff5f63579127940991dd0ead357f40e17d18..01b5816f8edab49b424afde7ea88baa37c620b64 100644
--- a/src/mips/codegen-mips.cc
+++ b/src/mips/codegen-mips.cc
@@ -305,6 +305,11 @@ void CodeGenerator::GenerateFastCharCodeAt(ZoneList<Expression*>* args) {
 }
 
 
+void CodeGenerator::GenerateCharFromCode(ZoneList<Expression*>* args) {
+  UNIMPLEMENTED_MIPS();
+}
+
+
 void CodeGenerator::GenerateIsArray(ZoneList<Expression*>* args) {
   UNIMPLEMENTED_MIPS();
 }