[libc] fix inconsistent ninja targets #126318
Description
One thing that I noticed was that we have a mix of ninja targets that sometimes use hypens, sometimes underscores, sometimes "unittests" sometimes "tests."
Example:
$ ninja libc_
libc_arpa_inet_unittests libc_sys_auxv_unittests
libc_assert_unittests libc_sys_epoll_unittests
libc_dirent_unittests libc_sys_mman_unittests
libc_errno_unittests libc_sys_prctl_unittests
libc_execv_test_normal_exit libc_sys_random_unittests
libc_execv_test_signal_exit libc_sys_resource_unittests
libc_fcntl_unittests libc_sys_select_unittests
libc_fenv_unittests libc_sys_sendfile_unittests
libc_include_tests libc_sys_socket_unittests
libc_inttypes_tests libc_sys_stat_unittests
libc_poll_unittests libc_sys_statvfs_unittests
libc_posix_spawn_test_binary libc_system_str_to_float_comparison_test
libc_pthread_unittests libc_sys_uio_unittests
libc_sched_unittests libc_sys_utsname_unittests
libc_search_unittests libc_sys_wait_unittests
libc_setjmp_unittests libc_termios_unittests
libc_signal_unittests libc_time_unittests
libc_spawn_unittests libc_unistd_unittests
libc_stack_chk_guard_unittests libc_unittest_tests
libc_stdio_unittests libc_wchar_unittests
libc_str_to_float_comparison_test
$ ninja libc-
libc-complex-unittests libc-rpc-tests
libc-cpp-utils-tests libc-startup
libc-ctype-tests libc-startup-tests
libc-fixed-point-tests libc-stdbit-tests
libc-fputil-tests libc-stdfix-tests
libc-fuzzer libc-stdlib-tests
libc-hermetic-tests libc-strings-tests
libc-integration-tests libc-string-tests
libc-locale-tests libc-support-tests
libc-long-running-tests libc-support-threads-integration-tests
libc-math-smoke-tests libc-support-threads-tests
libc-math-unittests libc-support-time-tests
libc-osutil-tests libc-threads-integration-tests
libc-pthread-integration-tests libc-unit-testsPersonally, the underscores and unittests look way more consistent to me. But I think "unittests" is also somewhat overloaded since we have a different concept of unittests vs hermetic tests, and the ninja targets with unittests imply BOTH (I think). So I don't particularly care what we ultimately go with, as long as were consistent.
I have a weak preference to make most of these just: libc_stdio_tests and libc_string_tests etc. (i.e. libc_{header}_tests). Thoughts?