files: extract code for extra filtering of the `removed` entry into copies
We want to reduce the set of `removed` files that to the set of files actually
removed. That `removed` set is used as of the changeset centric algorithm,
having smaller sets means less processing and faster computation.
In this changeset we extract the code to be a function of it own. We will make
use of it in the next changesets.
Differential Revision: https://phab.mercurial-scm.org/D8588
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}