Merge branch 'time64' of https://github.com/t-8ch/util-linux

* 'time64' of https://github.com/t-8ch/util-linux:
  build-sys: (tests) validate that time_t is 64bit
  meson: try to always use 64bit time support on glibc
  build-sys: try to always use 64bit time support on glibc
  build-sys: backport autoconf year2038 macros
  tests: add sysinfo to show sizeof(time_t)
  tests: constify a sysinfo helpers struct