Fix error reporting happens internally.

com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/REngine.java

@@ -343,6 +343,16 @@ final class REngine implements Engine {
             RContext.threadLocalContext.set(context);
             try {
                 return ((REngine) context.getThisEngine()).runCall(callTarget, context.stateREnvironment.getGlobalFrame(), true, true);
+            } catch (ReturnException ex) {
+                return ex.getResult();
+            } catch (DebugExitException | QuitException | BrowserQuitException e) {
+                throw e;
+            } catch (RError e) {
+                // TODO normal error reporting is done by the runtime
+                RInternalError.reportError(e);
+                return null;
+            } catch (Throwable t) {
+                return t;
             } finally {
                 RContext.threadLocalContext.set(oldContext);
             }

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/context/DefaultConsoleHandler.java

@@ -29,47 +29,27 @@ import com.oracle.truffle.api.TruffleLanguage.Env;
 public class DefaultConsoleHandler implements ConsoleHandler {
 
     private final BufferedReader in;
-    private final OutputStreamWriter out;
+    private final PrintStream out;
 
     public DefaultConsoleHandler(Env env) {
         in = new BufferedReader(new InputStreamReader(env.in()));
-        out = new OutputStreamWriter(env.out());
+        out = new PrintStream(env.out());
     }
 
     public void println(String s) {
-        try {
-            out.append(s).append('\n');
-            out.flush();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+        out.println(s);
     }
 
     public void print(String s) {
-        try {
-            out.append(s).append('\n');
-            out.flush();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+        out.print(s);
     }
 
     public void printErrorln(String s) {
-        try {
-            out.append(s).append('\n');
-            out.flush();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+        out.println(s);
     }
 
     public void printError(String s) {
-        try {
-            out.append(s).append('\n');
-            out.flush();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
+        out.print(s);
     }
 
     public String readLine() {