tests: demonstrate that copy info in changeset gets lost on amend
When copy information is stored in changesets, it gets lost on
amend. We didn't notice that until now because our users at Google
have the config set to `compatibility`, which means copy information
is stored in both changeset and filelogs.
Differential Revision: https://phab.mercurial-scm.org/D12386
{
// 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)
}