+ * Convert multiple arrays of float to an array of interleaved float.
+ *
+ * @param dst destination array of interleaved float.
+ * constraints: 16-byte aligned
+ * @param src source array of float arrays, one for each channel.
+ * constraints: 16-byte aligned
+ * @param len number of elements to convert.
+ * constraints: multiple of 8
+ * @param channels number of channels