tests/svn/svndump-empty.sh

typing: attempt to remove @overloads in the platform module for stdlib methods

This is mostly successful, as examining util.pyi, posix.pyi, and windows.pyi
after a pytype run shows that the type overloads for `oslink`, `readlink`,
`removedirs`, `rename`, `split`, and `unlink` have been removed.  (Some of these
still have an @overload, but the differences are the variable names, not the
types.)  However, @overloads remain for `abspath` and `normpath` for some
reason.

It's useful to redefine these methods for the type checking phase because in
addition to excluding str and PathLike variants, some of these functions have
optional args in stdlib that aren't implemented in the custom implementation on
Windows, and we want the type checking to flag that instead of assuming it's an
allowable overload everywhere.

One last quirk I noticed that I can't explain- `pycompat.TYPE_CHECKING` is
always False, so the conditionals need to check `typing.TYPE_CHECKING` directly.
I tried dropping the custom code for assigning `pycompat.TYPE_CHECKING` and
simply did `from typing import TYPE_CHECKING` directly in pycompat.py, and used
`pycompat.TYPE_CHECKING` for the conditional here... and pytype complained that
`pycompat` doesn't have the `TYPE_CHECKING` variable.

#!/bin/sh
#
# Use this script to generate empty.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
mkdir branches
mkdir tags
cd ..

svnadmin create svn-repo
svnurl=file://`pwd`/svn-repo
svn import project-orig $svnurl -m "init projA"

svn co $svnurl project
cd project
mkdir trunk/dir
echo a > trunk/dir/a
svn add trunk/dir
svn ci -m adddir

echo b > trunk/b
svn add trunk/b
svn ci -m addb

echo c > c
svn add c
svn ci -m addc
cd ..

# svnsync repo/trunk/dir only so the last two revisions are empty
svnadmin create svn-empty
cat > svn-empty/hooks/pre-revprop-change <<EOF
#!/bin/sh
exit 0
EOF
chmod +x svn-empty/hooks/pre-revprop-change
svnsync init --username svnsync file://`pwd`/svn-empty file://`pwd`/svn-repo/trunk/dir
svnsync sync file://`pwd`/svn-empty
svn log -v file://`pwd`/svn-empty

svnadmin dump svn-empty > ../empty.svndump