BACKPORT: fix(FTBFS): meson: raise C++ standard to C++17

LLVM 16 requires this since [0] and instead of just going all over the
various directories and adding overrides it should be easier to just
raise this globally. GCC supports C++17 since GCC 8 (2018), Clang since
version 5 (2017). Debian Buster (oldstable) has GCC 8.3 and Clang 7.0,
so all major distributions should have this and there shouldn't be an
issue with bumping.

[0] <https://github.com/llvm/llvm-project/commit/b4e9977fc18405d4a11cbaf1975bcadbf75920b8>

Closes: <https://gitlab.freedesktop.org/mesa/mesa/-/issues/7031>
Signed-off-by: Kai Wasserbäch <kai@dev.carbon-project.org>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: David Heidelberg <david.heidelberg@collabora.com>
Reviewed-by: Ganesh Belgur Ramachandra <ganesh.belgurramachandra@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17966>
(cherry picked from commit f9057cea517e01e05f08f00a741aad5bae154d62)

BUG=b:258423065
TEST=CQ

Change-Id: I5ec20d5ccb2eb07f299f41106df2606e0bd90cdf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/mesa/+/4017893
Commit-Queue: Chia-I Wu <olv@google.com>
Reviewed-by: Matt Turner <msturner@google.com>
Tested-by: Chia-I Wu <olv@google.com>
Reviewed-by: Ilja Friedel <ihf@chromium.org>
2 files changed