dillon1000/react

replace-fork should not clear uncommitted changes (#22348)

The replace-fork script depends on ESLint to fix the reconciler imports
— `.old` -> `.new` or vice versa. If ESLint crashes, it can leave the
imports in an incorrect state.

As a convenience, @bvaughn updated the script to automatically run
`git checkout -- .` if the ESLint command fails. An unintended
consequence of the strategy is that if the working directory is not
clean, then any uncommitted changes will be lost.

We need a better strategy for this that prevents the accidental loss of
work. One option is to exit early if the working directory is not clean
before you run the script, though that affects the usability of
the script.

An ideal solution would reset the working directory back to whatever
state it was in before the script ran, perhaps by stashing all the
changes and restoring them if the script aborts.

Until we think of something better, I've commmented out the branch.