Revert "dir.c: make 'git-status --ignored' work within leading directories"

Revert "dir.c: make 'git-status --ignored' work within leading directories"

Commit be8a84c52669 ("dir.c: make 'git-status --ignored' work within
leading directories", 2013-04-15) noted that
   git status --ignored <SOMEPATH>
would not list ignored files and directories within <SOMEPATH> if
<SOMEPATH> was untracked, and modified the behavior to make it show
them.  However, it did so via a hack that broke consistency; it would
show paths under <SOMEPATH> differently than a simple
   git status --ignored | grep <SOMEPATH>
would show them.  A correct fix is slightly more involved, and
complicated slightly by this hack, so we revert this commit (but keep
corrected versions of the testcases) and will later fix the original
bug with a subsequent patch.

Some history may be helpful:

A very, very similar case to the commit we are reverting was raised in
commit 48ffef966c76 ("ls-files: fix overeager pathspec optimization",
2010-01-08); but it actually went in somewhat the opposite direction.  In
that commit, it mentioned how
   git ls-files -o --exclude-standard t/
used to show untracked files under t/ even when t/ was ignored, and then
changed the behavior to stop showing untracked files under an ignored
directory.  More importantly, this commit considered keeping this
behavior but noted that it would be inconsistent with the behavior when
multiple pathspecs were specified and thus rejected it.

The reason for this whole inconsistency when one pathspec is specified
versus zero or two is because common prefixes of pathspecs are sent
through a different set of checks (in treat_leading_path()) than normal
file/directory traversal (those go through read_directory_recursive()
and treat_path()).  As such, for consistency, one needs to check that
both codepaths produce the same result.

Revert commit be8a84c526691667fc04a8241d93a3de1de298ab, except instead
of removing the testcase it added, modify it to check for correct and
consistent behavior.  A subsequent patch in this series will fix the
testcase.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>