a modifier resolves symlinks - docs say it shouldn't

[Langbart <Langbart@xxxxxxxxxxxxxx>]

Guten Tag, 

the :a modifier doc claims it operates on the logical path, but testing when CWD
is a symlink says otherwise.

```txt
man zshexpn | grep -C9 'not the physical directory'
       modifiers also work on the result of filename generation and parameter
       expansion, except where noted.

       a      Turn a file name into an absolute path:  prepends the current
              directory, if necessary; remove `.' path segments; and remove
              `..' path segments and the segments that immediately precede
              them.

              This transformation is agnostic about what is in the filesystem,
              i.e. is on the logical, not the physical directory.  It takes
              place in the same manner as when changing directories when
              neither of the options CHASE_DOTS or CHASE_LINKS is set.  For
              example, `/before/here/../after' is always transformed to
              `/before/after', regardless of whether `/before/here' exists or
              what kind of object (dir, file, symlink, etc.) it is.

       A      Turn a file name into an absolute path as the `a' modifier does,
              and then pass the result through the realpath(3) library
              function to resolve symbolic links.
```

To reproduce:

`test.zsh` script

```zsh
#!/usr/bin/env zsh --no-rcs

tmp_dir=$(mktemp -d)
{
  mkdir -p ${tmp_dir}/real
  ln -s ${tmp_dir}/real ${tmp_dir}/link
  cd ${tmp_dir}/link
  dir=x

  echo "PWD     ${PWD}"
  echo "pwd -L  $(pwd -L)"
  echo "pwd -P  $(pwd -P)"
  echo
  echo ":a      ${dir:a}"
  echo ":A      ${dir:A}"
  echo ":P      ${dir:P}"
} always {
  rm -rf ${tmp_dir}
}
```

Expected for ':a':  /tmp/.../link/x

Actual   for ':a':  /tmp/.../real/x

```zsh
podman run --quiet --rm -v $PWD/test.zsh:/test.zsh:ro alpine sh -c '
apk add --quiet zsh
zsh /test.zsh'

PWD     /tmp/tmp.JcNaha/link
pwd -L  /tmp/tmp.JcNaha/link
pwd -P  /tmp/tmp.JcNaha/real

:a      /tmp/tmp.JcNaha/real/x
:A      /tmp/tmp.JcNaha/real/x
:P      /tmp/tmp.JcNaha/real/x
```

The issue came up in a bug report: https://github.com/junegunn/fzf/issues/4816

P.S. I also ran it on macOS (15.7.7) with a very recent zsh dev version; the
issue persists (ZSH_PATCHLEVEL zsh-5.9.0.2-test-325-ga58ad1a).