delete-changed or changed-delete conflicts can be resolved by mergetool, either
if some tool is passed and using or by user choose something on prompt.
If the user decides to keep the changed side, on commit we just reuse the parent
filenode. This is mostly fine unless we are in a distributed environment and
people are doing criss-cross merges.
Since, we don't have recursive merges or any other way of describing the end
result of the merge was an explicit choice and it should be differentiated from
it's ancestors, merge algo during criss-cross merges fails to take in account
the explicit choice made by user and end up with a what-can-be-said-wrong-merge.
The solution which we are trying to fix this is by creating a filenode on commit
instead of reusing the parent filenode. This helps differentiate between
pre-merged filenode and post-merge filenode and kind of tells about the choice
To implement creating new filenode functionality, we store info about these
files in mergestate so that we can read them on commit and force create a new