refactor/rename: don't make backups; overwrite in place, preserving inode.

This avoids littering the tree, and confusing some editors (e.g. Atom)
that expect the inode number to remain constant.

Change-Id: I2faeda1ed1b01e5e4cc720744ea3c99ab29e7333
Reviewed-on: https://go-review.googlesource.com/7664
Reviewed-by: Robert Griesemer <gri@golang.org>
1 file changed