array-bounds warning when compiling llfs with GCC 12

[haoning66]

Our project depends on llfs and we are upgrading GCC from 11 to 12, a new warning shows up:

/usr/local/bin/ccache /opt/x86_64-linux-gnu/bin/g++ -DBOOST_ERROR_CODE_HEADER_ONLY -DBOOST_STACKTRACE_ADDR2LINE_LOCATION="/usr/bin/addr2line" -DBOOST_STACKTRACE_USE_ADDR2LINE -DBOOST_STACKTRACE_USE_BACKTRACE -DBOOST_STACKTRACE_USE_NOOP -DFUSE_USE_VERSION=35 -DGFLAGS_DLL_DECLARE_FLAG="" -DGFLAGS_DLL_DEFINE_FLAG="" -D_BITS_UIO_EXT_H=1 -I/local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/build/Release -I/local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/libfu9a681877c429d/p/include/fuse3 -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/batte1dff8a2946d33/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/pcg-c4aa2cafcf36e3/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/proto4c4dac32c1fed/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/boost54a4f2bd8264f/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/libbaacacf737cb74b/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/glog01cd0c9915f3e/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/gflaga472e1ead60be/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/libun60b65e1489426/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/llfs2fc70535df331/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/cli11387b72d23d771/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/gtestac4120864d9e7/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/opens42d679073e3a9/p/include -isystem /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/libur3c2f6731755c1/p/include -fno-omit-frame-pointer -m64 -fno-omit-frame-pointer -O3 -DNDEBUG -fno-diagnostics-color -D_GNU_SOURCE -fno-omit-frame-pointer -Wall -Wextra -Werror -Werror=switch-enum -Wswitch-enum -Wsuggest-override -Woverloaded-virtual -DBATT_HEADER_ONLY=0 -DBATT_WITH_GLOG=1 -DBATT_WITH_PROTOBUF=1 -std=c++17 -D_BITS_UIO_EXT_H=1 -std=c++17 -MD -MT CMakeFiles/turtle_tree.dir/turtle/tree/testing/fake_batch.cpp.o -MF CMakeFiles/turtle_tree.dir/turtle/tree/testing/fake_batch.cpp.o.d -o CMakeFiles/turtle_tree.dir/turtle/tree/testing/fake_batch.cpp.o -c /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/testing/fake_batch.cpp
In file included from /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/leaf_layout.hpp:8,
from /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/edit_batch.hpp:5,
from /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/testing/fake_batch.hpp:5,
from /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/testing/fake_batch.cpp:1:
In member function 'void llfs::PackedArray::initialize(I) [with I = unsigned int; T = turtle_db::PackedEdit]',
inlined from 'turtle_db::testing::FakeBatch::FakeBatch(const turtle_db::TreeOptions&)' at /local/gitlab-runner-local-cache/.conan_2.2.2/p/b/turtl6fb4171fa3a98/b/src/turtle/tree/testing/fake_batch.cpp:20:39:
/local/gitlab-runner-local-cache/.conan_2.2.2/p/b/llfs2fc70535df331/p/include/llfs/packed_array.hpp:45:16: error: 'void* memset(void*, int, size_t)' offset [0, 6] is out of the bounds [0, 0] [-Werror=array-bounds]
45 | std::memset(this, 0, sizeof(PackedArray));
| ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors