[PATCH v2 0/5] test-lib-functions.sh: trickery to make -x less verbose

This series makes the "-x" output less verbose for our various helper
functions, mainly using the trickery of feeding "$@" to "test" to rely
on it to die when given too many arguments.

Since v2[1] I ejected the patch to make the "test_line_count" function
unsafer per Junio's feedback.

The test_file_size has lost its "BUG" invocation, but is now safe as
we do that check in the test helper, as shown in 5/5 we fixed one
previous mild regression while doing that.

The 3-4/5 patches are just trivial "while we're at it" work.

1. http://lore.kernel.org/git/cover-0.3-0000000000-20210420T122706Z-avarab@gmail.com (local)

Ævar Arnfjörð Bjarmason (5):
  test-lib-functions: normalize test_path_is_missing() debugging
  Revert and amend "test-lib-functions: assert correct parameter count"
  test helpers: remove unused test-tool path-utils slice-tests
  test-helpers: rename "path-utils is_valid_path" to "is-valid-paths"
  test-helpers: split "file-size" into "file-size(s)"

 t/helper/test-path-utils.c  | 44 ++++++------------------
 t/t0060-path-utils.sh       |  2 +-
 t/t1050-large.sh            |  2 +-
 t/t5319-multi-pack-index.sh |  6 ++--
 t/test-lib-functions.sh     | 67 ++++++++++++++++---------------------
 5 files changed, 45 insertions(+), 76 deletions(-)

Range-diff against v1:
1:  fd33f6d71f0 = 1:  ba9d6251ad5 test-lib-functions: normalize test_path_is_missing() debugging
2:  67ddd821dfa = 2:  5f8e5ad27f5 Revert and amend "test-lib-functions: assert correct parameter count"
3:  8fd51861b59 < -:  ----------- test-lib-functions: remove last two parameter count assertions
-:  ----------- > 3:  44948c6ace9 test helpers: remove unused test-tool path-utils slice-tests
-:  ----------- > 4:  ae5dc5d03b3 test-helpers: rename "path-utils is_valid_path" to "is-valid-paths"
-:  ----------- > 5:  947791d9535 test-helpers: split "file-size" into "file-size(s)"
-- 
2.31.1.721.gbeb6a21927