Adds a versioned .githooks/pre-commit that builds z3 and runs the
z3test regression suite (scripts/test_benchmarks.py over
regressions/smt2) as a precondition for every commit. Enable with
'git config core.hooksPath .githooks'.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
