Revert "buffer: convert offset & length to int properly"

This reverts commit ca37fa5.

A test provided by the commit fails on most (but not all) platforms on
CI.

PR-URL: nodejs#9814
Ref: nodejs#9492
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

lib/buffer.js

@@ -238,7 +238,7 @@ function fromArrayLike(obj) {
 }
 
 function fromArrayBuffer(obj, byteOffset, length) {
-  byteOffset = internalUtil.toInteger(byteOffset);
+  byteOffset >>>= 0;
 
   const maxLength = obj.byteLength - byteOffset;
 
@@ -248,7 +248,7 @@ function fromArrayBuffer(obj, byteOffset, length) {
   if (length === undefined) {
     length = maxLength;
   } else {
-    length = internalUtil.toLength(length);
+    length >>>= 0;
     if (length > maxLength)
       throw new RangeError("'length' is out of bounds");
   }

lib/internal/util.js

@@ -161,21 +161,3 @@ exports.cachedResult = function cachedResult(fn) {
     return result;
   };
 };
-
-/*
- * Implementation of ToInteger as per ECMAScript Specification
- * Refer: http://www.ecma-international.org/ecma-262/6.0/#sec-tointeger
- */
-const toInteger = exports.toInteger = function toInteger(argument) {
-  const number = +argument;
-  return Number.isNaN(number) ? 0 : Math.trunc(number);
-};
-
-/*
- * Implementation of ToLength as per ECMAScript Specification
- * Refer: http://www.ecma-international.org/ecma-262/6.0/#sec-tolength
- */
-exports.toLength = function toLength(argument) {
-  const len = toInteger(argument);
-  return len <= 0 ? 0 : Math.min(len, Number.MAX_SAFE_INTEGER);
-};