Properly recover from failed compilation.

BUG=5955072

We used to call delete, which did not update the Context's view of the world,
leading to potential segfaults on Context teardown. This change also enables
exceptions to be thrown when runtime errors are encountered.

Change-Id: If63578efff2d7dd03639da1049c1a5ebc69fde35

graphics/java/android/renderscript/RenderScript.java

@@ -837,7 +837,7 @@ public class RenderScript {
                         mRS.mErrorCallback.mErrorNum = subID;
                         mRS.mErrorCallback.run();
                     } else {
-                        //throw new RSRuntimeException("Received error num " + subID + ", details: " + e);
+                        throw new RSRuntimeException("Received error num " + subID + ", details: " + e);
                     }
                     continue;
                 }