tools: relax lint rule for regexps

Relax the rule for maximum line length in JS files if the line contains
a regular expression literal. This will avoid the need to convert a
regular expression literal into a RegExp constructor call broken across
multiple lines in order to satisfy the maximum line length rule. That
practice hampers readability.

PR-URL: #12807
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

.eslintrc.yaml

@@ -106,7 +106,10 @@ rules:
   key-spacing: [2, {mode: minimum}]
   keyword-spacing: 2
   linebreak-style: [2, unix]
-  max-len: [2, {code: 80, ignoreUrls: true, tabWidth: 2}]
+  max-len: [2, {code: 80,
+                ignoreRegExpLiterals: true,
+                ignoreUrls: true,
+                tabWidth: 2}]
   new-parens: 2
   no-mixed-spaces-and-tabs: 2
   no-multiple-empty-lines: [2, {max: 2, maxEOF: 0, maxBOF: 0}]