It turns out to be painful to require linking against -lrt on
GNU/Linux, as that makes it harder to link Go code into C programs.
Instead just call the timer syscalls directly. That is what the
upstream library does anyhow.
gcc/go/
* gospec.cc: Revert 2022-02-09 change:
(RTLIB, RT_LIBRARY): Don't define.
(lang_specific_driver): Don't add -lrt if linking statically
on GNU/Linux.
gotools/
* configure.ac: Revert 2022-02-09 change:
(RT_LIBS): Don't define.
* Makefile.am (check-runtime): Don't set GOLIBS to $(RT_LIBS).
* configure, Makefile.in: Regenerate.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/385475
58aeb75d40