[3.13] GH-130396: Treat clang -Og as optimized for gdb tests (GH-130550) (#130572)

GH-130396: Treat clang -Og as optimized for gdb tests (GH-130550)
(cherry picked from commit 129db32d6f2d7f450d2741da6a222c18e458c61b)

Co-authored-by: Mark Shannon <mark@hotpy.org>