This enables storing errno in the thread local storage area.
With this enabled, a syscall to access errno can be avoided
when userspace is also enabled.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
move misc/errno_private.h to sys/errno_private.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>