[PATCH v1 0/4] Cleanup pass on special test setups

As documented in t/README, the whole test suite can be run to test some special features that cannot be easily covered by a few specific test cases.

Not all of these that exist in the code have been named consistantly and documented in r/README which leads to a discoverability problem. Update several of these variables to follow the same naming pattern and document them properly.

To facilitate transitioning from the old names to the new names, add logic in t/test-lib.sh to give an error when the old variable is set to let people know they need to update their environment to use the new variable. If the new variable is also set, just give a warning so they can eventually remove the old variable.

Base Ref: v2.19.0
Web-Diff: https://github.com/benpeart/git/commit/eff73d737e
Checkout: git fetch https://github.com/benpeart/git git-test-cleanup-v1 && git checkout eff73d737e

Ben Peart (4):
  correct typo/spelling error in t/README
  fsmonitor: update GIT_TEST_FSMONITOR support
  read-cache: update TEST_GIT_INDEX_VERSION support
  preload-index: update GIT_FORCE_PRELOAD_TEST support

 Makefile                    |  6 +++---
 config.c                    |  2 +-
 preload-index.c             |  3 ++-
 t/README                    | 13 ++++++++++++-
 t/t1700-split-index.sh      |  2 +-
 t/t7519-status-fsmonitor.sh |  6 +++---
 t/test-lib.sh               | 37 +++++++++++++++++++++++++++++++++++--
 7 files changed, 57 insertions(+), 12 deletions(-)

base-commit: 1d4361b0f344188ab5eec6dcea01f61a3a3a1670