dns: report out of memory properly

This addresses a part of a TODO by properly reporting an out of
memory error to the user instead of reporting `ENOTFOUND`.

PR-URL: #20317
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

lib/internal/errors.js

@@ -29,7 +29,6 @@ const READABLE_OPERATOR = {
 
 const {
   errmap,
-  UV_EAI_MEMORY,
   UV_EAI_NODATA,
   UV_EAI_NONAME
 } = process.binding('uv');
@@ -640,9 +639,7 @@ function dnsException(code, syscall, hostname) {
   if (typeof code === 'number') {
     // FIXME(bnoordhuis) Remove this backwards compatibility nonsense and pass
     // the true error to the user. ENOTFOUND is not even a proper POSIX error!
-    if (code === UV_EAI_MEMORY ||
-        code === UV_EAI_NODATA ||
-        code === UV_EAI_NONAME) {
+    if (code === UV_EAI_NODATA || code === UV_EAI_NONAME) {
       code = 'ENOTFOUND'; // Fabricated error name.
     } else {
       code = lazyInternalUtil().getSystemErrorName(code);

test/parallel/test-http-dns-error.js

@@ -29,7 +29,7 @@ const assert = require('assert');
 const http = require('http');
 const https = require('https');
 
-const host = '*'.repeat(256);
+const host = '*'.repeat(64);
 const MAX_TRIES = 5;
 
 let errCode = 'ENOTFOUND';

test/parallel/test-net-dns-error.js

@@ -25,7 +25,7 @@ const common = require('../common');
 const assert = require('assert');
 const net = require('net');
 
-const host = '*'.repeat(256);
+const host = '*'.repeat(64);
 const errCode = common.isOpenBSD ? 'EAI_FAIL' : 'ENOTFOUND';
 
 const socket = net.connect(42, host, common.mustNotCall());