Detaching doesn't work yet, the setsid() call fails and leaves the child process
attached to the parent's session.
Revert "test: Add test case for spawning detached child processes."
Revert "win: Implement options.detached for uv_spawn() for Windows."
Revert "unix: Implement options.detached for uv_spawn() for unix."
Revert "Add "detached" member to uv_process_options_t to denote whether a child
process should spawn detached from its parent."
This reverts commit ea9baef95c.
This reverts commit e99fdf0df6.
This reverts commit 149d32cb96.
This reverts commit b3e0ad4db8.
Do not check for minimum kernel and glibc versions, just check that the kernel
headers export the syscall number and invoke the syscall directly. Effectively
bypasses glibc.
libuv uses feature checks to determine if newer syscalls like pipe2() are
available. This works fine until someone compiles libuv against kernel headers
that are newer than the actual kernel our software runs on.
Fall back to traditional (but race-y!) syscalls when the kernel reports ENOSYS
or EINVAL.
