because of https://bugzilla.redhat.com/show_bug.cgi?id=2278689,
the rebuilt abseil package provided by fedora has different settings
than the ones if the tree is built with the sanitizer enabled. this
inconsistency leads to a crash.
to address this problem, we have to reinstate the abseil submodule, so
we can built it with the same compiler options with which we build the
tree.
in this change
* Revert "build: drop abseil submodule, replace with distribution abseil"
* update CMake building system with abseil header include settings
* bump up the abseil submodule to the latest LTS branch of abseil:
lts_2024_01_16
* update scylla-gdb.py to adapt to the new structure of
flat_hash_map
This reverts commit 8635d24424.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18511