ab/cmake-nix-and-ci (was: What's cooking in git.git (Nov 2022, #01; Thu, 3))

> * ab/cmake-nix-and-ci (2022-11-02) 12 commits
>  - CI: add a "linux-cmake-test" to run cmake & ctest on linux
>  - cmake: copy over git-p4.py for t983[56] perforce test
>  - cmake: support GIT_TEST_OPTS, abstract away WIN32 defaults
>  - Makefile + cmake: use environment, not GIT-BUILD-DIR
>  - test-lib.sh: support a "GIT_TEST_BUILD_DIR"
>  - cmake: set "USE_LIBPCRE2" in "GIT-BUILD-OPTIONS" for test-lib.sh
>  - cmake & test-lib.sh: add a $GIT_SOURCE_DIR variable
>  - cmake: chmod +x the bin-wrappers/* & SCRIPT_{SH,PERL} & git-p4
>  - cmake: don't copy chainlint.pl to build directory
>  - cmake: update instructions for portable CMakeLists.txt
>  - cmake: don't "mkdir -p" and "cd" in build instructions
>  - cmake: increase test timeout on Windows only
>
>  Fix assorted issues with CTest on *nix machines.
>
>  Waiting for review.
>  source: <cover-v3-00.12-00000000000-20221101T225022Z-avarab@gmail.com>