bpo-38965: Fix faulthandler._stack_overflow() on GCC 10 (GH-17467)


Use the "volatile" keyword to prevent tail call optimization
on any compiler, rather than relying on compiler specific pragma.
(cherry picked from commit 8b787964e0a647caa0558b7c29ae501470d727d9)

Co-authored-by: Victor Stinner <vstinner@python.org>
2 files changed