Add "const". And clean up.

Change-Id: I70e6994a0cd1d897e6981d5642108fee1324708f
diff --git a/lib/ExecutionEngine/Script.cpp b/lib/ExecutionEngine/Script.cpp
index 085e7c8..2030db9 100644
--- a/lib/ExecutionEngine/Script.cpp
+++ b/lib/ExecutionEngine/Script.cpp
@@ -325,7 +325,7 @@
 }
 #endif
 
-int Script::internalCompile(CompilerOption &option) {
+int Script::internalCompile(const CompilerOption &option) {
   // Create the ScriptCompiled object
   mCompiled = new (std::nothrow) ScriptCompiled(this);