jni_ vec_ atan2
fun jni_vec_atan2(env: CPointer<JNIEnvVar>, thisObject: jobject, a: jdoubleArray, aOffset: jint, aSize: jint, b: jdoubleArray, bOffset: jint)
fun jni_vec_atan2(env: CPointer<JNIEnvVar>, thisObject: jobject, a: jdoubleArray, aOffset: jint, aSize: jint, b: jdoubleArray, bOffset: jint)