buffer: remove MAX_SAFE_INTEGER check on length

MAX_SAFE_INTEGER is millions of times larger than the largest buffer
allowed in Node.js. There is no need to squash the length down to
MAX_SAFE_INTEGER. Removing that check results in a small but
statistically significant increase for Buffer.from() operating on
ArrayBuffers in some situations.

PR-URL: https://github.com/nodejs/node/pull/14131
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>

lib/buffer.js

@@ -354,8 +354,6 @@ function fromArrayBuffer(obj, byteOffset, length) {
     if (length !== length) {
       length = 0;
     } else if (length > 0) {
-      length = (length < Number.MAX_SAFE_INTEGER ?
-                length : Number.MAX_SAFE_INTEGER);
       if (length > maxLength)
         throw new RangeError("'length' is out of bounds");
     } else {