lib: remove v8_prof_polyfill from eslint ignore list

.eslintignore

@@ -1,5 +1,4 @@
 node_modules
-lib/internal/v8_prof_polyfill.js
 lib/punycode.js
 test/addons/??_*
 test/fixtures

lib/internal/v8_prof_polyfill.js

@@ -25,7 +25,10 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-/* eslint-disable no-restricted-globals */
+'use strict';
+
+/* eslint-disable node-core/prefer-primordials */
+/* global Buffer, console */
 
 module.exports = { versionCheck };
 
@@ -37,7 +40,7 @@ if (module.id === 'internal/v8_prof_polyfill') return;
 // Node polyfill
 const fs = require('fs');
 const cp = require('child_process');
-const os = {
+const os = { // eslint-disable-line no-unused-vars
   system: function(name, args) {
     if (process.platform === 'linux' && name === 'nm') {
       // Filter out vdso and vsyscall entries.
@@ -51,28 +54,29 @@ const os = {
     let out = cp.spawnSync(name, args).stdout.toString();
     // Auto c++filt names, but not [iItT]
     if (process.platform === 'darwin' && name === 'nm') {
-      // nm prints an error along the lines of "Run xcodebuild -license" and
+      // `nm` prints an error along the lines of "Run xcodebuild -license" and
       // exits when Xcode hasn't been properly installed or when its license
       // hasn't been accepted yet. Basically any mention of xcodebuild in
       // the output means the nm command is non-functional.
       const match = out.match(/(?:^|\n)([^\n]*xcodebuild[^\n]*)(?:\n|$)/);
+      // eslint-disable-next-line no-restricted-syntax
       if (match) throw new Error(match[1]);
       out = macCppfiltNm(out);
     }
     return out;
   }
 };
-const print = console.log;
-function read(fileName) {
+const print = console.log; // eslint-disable-line no-unused-vars
+function read(fileName) { // eslint-disable-line no-unused-vars
   return fs.readFileSync(fileName, 'utf8');
 }
-const quit = process.exit;
+const quit = process.exit; // eslint-disable-line no-unused-vars
 
 // Polyfill "readline()".
-const logFile = arguments[arguments.length - 1];
+const logFile = arguments[arguments.length - 1]; // eslint-disable-line no-undef
 try {
   fs.accessSync(logFile);
-} catch(e) {
+} catch {
   console.error('Please provide a valid isolate file as the final argument.');
   process.exit(1);
 }
@@ -121,8 +125,8 @@ function versionCheck(firstLine, expected) {
   // whereas process.versions.v8 is either "$major.$minor.$build-$embedder" or
   // "$major.$minor.$build.$patch-$embedder".
   firstLine = firstLine.split(',');
-  const curVer = expected.split(/[.\-]/);
-  if (firstLine.length !== 6 && firstLine.length !== 7 ||
+  const curVer = expected.split(/[.-]/);
+  if ((firstLine.length !== 6 && firstLine.length !== 7) ||
       firstLine[0] !== 'v8-version') {
     return 'Unable to read v8-version from log file.';
   }
@@ -140,13 +144,11 @@ function macCppfiltNm(out) {
   if (entries === null)
     return out;
 
-  entries = entries.map((entry) => {
-    return entry.replace(CLEAN_RE, '')
-  });
+  entries = entries.map((entry) => entry.replace(CLEAN_RE, ''));
 
   let filtered;
   try {
-    filtered = cp.spawnSync('c++filt', [ '-p' , '-i' ], {
+    filtered = cp.spawnSync('c++filt', [ '-p', '-i' ], {
       input: entries.join('\n')
     }).stdout.toString();
   } catch {