assert: use less read operations

This reduces the total amount of reads when using `assert.ok()` with
a falsy value. That increases the read performance significantly.

Also remove a comment that can not be addressed.

PR-URL: #27525
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

lib/assert.js

@@ -172,8 +172,8 @@ function getCode(fd, line, column) {
   let lines = 0;
   // Prevent blocking the event loop by limiting the maximum amount of
   // data that may be read.
-  let maxReads = 64; // bytesPerRead * maxReads = 512 kb
-  const bytesPerRead = 8192;
+  let maxReads = 32; // bytesPerRead * maxReads = 512 kb
+  const bytesPerRead = 16384;
   // Use a single buffer up front that is reused until the call site is found.
   let buffer = Buffer.allocUnsafe(bytesPerRead);
   while (maxReads-- !== 0) {
@@ -619,11 +619,6 @@ function checkIsPromise(obj) {
   // Accept native ES6 promises and promises that are implemented in a similar
   // way. Do not accept thenables that use a function as `obj` and that have no
   // `catch` handler.
-
-  // TODO: thenables are checked up until they have the correct methods,
-  // but according to documentation, the `then` method should receive
-  // the `fulfill` and `reject` arguments as well or it may be never resolved.
-
   return isPromise(obj) ||
     obj !== null && typeof obj === 'object' &&
     typeof obj.then === 'function' &&