fcleanup function perfomance speed up

[vamp]

return nm.replace(/[^{\w\s\.\|`]/g, function( ch ) {}

return "
" + ch;

});

vs

nm.replace(/(?=[^{\w\s\.\|`])/g, '
');}

[vamp]

excuse me, "^" character was dropped from initial RegExp:  http://gyazo.com/cf062387ab1881de8771199fd5257e2f.png

[ridgerunner]

A fix very similar to this one was recently implemented (See #7062). However, the fix recommended here might be even faster. Only benchmarking can tell...

[snover]

Duplicate of #7062.