Fix race condition in standard_error process registration

Fix a race condition where the standard_error process could call
prim_tty:init/1 before being registered, causing a crash when prim_tty's
writer and reader processes attempt to derive their own registered names
from the parent process.

The issue was introduced in commit
ead7424 (PR #9116), which changed
prim_tty's reader and writer processes to dynamically derive their
registered names from their parent process name (e.g., 'standard_error'
-> 'standard_error_reader', 'standard_error_writer'). This was done
to support multiple TTY instances (stdout and stderr) with
distinct process names.

However, the standard_error:start/0 function had a race condition:
1. spawn(fun server/0) - creates process, starts executing immediately
2. register(?NAME, Id) - parent registers the spawned process
3. server() calls prim_tty:init() - may execute before step 2

When prim_tty:init/1 spawns writer/reader processes, they call
set_name(Parent, Postfix) which does: erlang:process_info(Parent,
registered_name)

If this executes before the parent completes registration, it returns []
instead of {registered_name, standard_error}, causing a pattern match
failure: "no match of right hand side value: []" at prim_tty.erl:674.

The fix moves the register/2 call into the spawned process itself,
ensuring it completes before prim_tty:init/1 is called. This eliminates
the race condition entirely.

Closes #10174

Author: NelsonVides

lib/kernel/src/standard_error.erl

@@ -62,12 +62,11 @@ init([]) ->
     end.
 
 start() ->
-    Id = spawn(fun server/0),
-    register(?NAME, Id),
-    Id.
+    spawn(fun server/0).
 
 server() ->
     process_flag(trap_exit, true),
+    register(?NAME, self()),
     ok = prim_tty:load(),
     TTY = prim_tty:init(#{ input => disabled,
                            output => cooked,