Merge pull request #2741 from arnarthor/master

Add fromStringWithEncoding and toString to Node_buffer

Author: bobzhang

jscomp/others/node_buffer.ml

@@ -31,3 +31,9 @@ external isBuffer : 'a -> bool = "Buffer.isBuffer"
 
 external fromString : string -> t = "Buffer.from"
 [@@bs.val]
+
+external fromStringWithEncoding : string -> ([ `ascii  | `utf8  | `utf16le  | `usc2  | `base64  | `latin1 | `binary  | `hex ] [@bs.string]) -> t = "from"
+[@@bs.val] [@@bs.scope "Buffer"]
+
+external toString : t -> string = ""
+[@@bs.send] [@@bs.scope "Buffer"]