Remove redundant check if ScriptEngine is closed.

Author: woess

graal-js/src/com.oracle.truffle.js.scriptengine/src/com/oracle/truffle/js/scriptengine/GraalJSScriptEngine.java

@@ -239,7 +239,6 @@ public Builder setOption(Builder builder, Object value) {
     private final GraalJSEngineFactory factory;
     private final Context.Builder contextConfig;
 
-    private volatile boolean closed;
     private boolean evalCalled;
 
     GraalJSScriptEngine(GraalJSEngineFactory factory) {
@@ -292,7 +291,6 @@ static Context createDefaultContext(Context.Builder builder) {
     @Override
     public void close() {
         getPolyglotContext().close();
-        closed = true;
     }
 
     /**
@@ -532,18 +530,12 @@ private static <T> T getInterfaceInner(Value thiz, Class<T> iface) {
 
     @Override
     public CompiledScript compile(String script) throws ScriptException {
-        if (closed) {
-            throw new IllegalStateException("Context already closed.");
-        }
         Source source = createSource(script, getContext());
         return compile(source);
     }
 
     @Override
     public CompiledScript compile(Reader reader) throws ScriptException {
-        if (closed) {
-            throw new IllegalStateException("Context already closed.");
-        }
         Source source = createSource(read(reader), getContext());
         return compile(source);
     }