dev-lang/go: 1.14: check running kernel version before compiling
Compilation will fail if the host is running certain versions of the
Linux kernel with the message: runtime: mlock of signal stack failed: 12
Note from williamh:
The original pr checked for kernel versions not listed in the upstream
issue, so I reworked it. Also, it used pkg_setup instead of pkg_pretend
for the checks.
Closes: https://bugs.gentoo.org/711884
Closes: https://github.com/gentoo/gentoo/pull/14868
Signed-off-by: William Hubbs <williamh@gentoo.org>