Import Abseil LTS version 20230802.0
Deal with files which contain pragma(s) suppressing important diagnostics:
inst/include/absl/base/internal/invoke.hinst/include/absl/container/internal/inlined_vector.hFiles which contain non-portable pragma(s):
inst/include/absl/base/internal/invoke.hinst/include/absl/container/inlined_vector.hinst/include/absl/functional/internal/any_invocable.hinst/include/absl/random/internal/explicit_seed_seq_test.ccinst/include/absl/strings/internal/cord_rep_flat.hinst/include/absl/types/internal/optional.hFiles which contain pragma(s) suppressing diagnostics:
inst/include/absl/algorithm/algorithm_test.ccinst/include/absl/container/inlined_vector.hinst/include/absl/container/internal/counting_allocator.hinst/include/absl/container/internal/raw_hash_set_test.ccinst/include/absl/functional/internal/any_invocable.hinst/include/absl/random/internal/explicit_seed_seq_test.ccinst/include/absl/random/internal/randen_detect.ccinst/include/absl/random/internal/randen_hwaes.ccinst/include/absl/strings/internal/cord_rep_flat.hinst/include/absl/strings/internal/str_format/bind_test.ccinst/include/absl/strings/internal/utf8_test.ccinst/include/absl/strings/str_split_test.ccinst/include/absl/types/internal/optional.h