repl: add async and await as keywords

PR-URL: #15566
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

Author: TimothyGu

lib/repl.js

@@ -1239,11 +1239,11 @@ function addStandardGlobals(completionGroups, filter) {
   // they just get in the way.
   if (filter) {
     completionGroups.push([
-      'break', 'case', 'catch', 'const', 'continue', 'debugger', 'default',
-      'delete', 'do', 'else', 'export', 'false', 'finally', 'for', 'function',
-      'if', 'import', 'in', 'instanceof', 'let', 'new', 'null', 'return',
-      'switch', 'this', 'throw', 'true', 'try', 'typeof', 'undefined', 'var',
-      'void', 'while', 'with', 'yield'
+      'async', 'await', 'break', 'case', 'catch', 'const', 'continue',
+      'debugger', 'default', 'delete', 'do', 'else', 'export', 'false',
+      'finally', 'for', 'function', 'if', 'import', 'in', 'instanceof', 'let',
+      'new', 'null', 'return', 'switch', 'this', 'throw', 'true', 'try',
+      'typeof', 'undefined', 'var', 'void', 'while', 'with', 'yield'
     ]);
   }
 }