LibCore: Add Core::System wrapper for disown()

Author: https://github.com/sppmacd
Commit: https://github.com/SerenityOS/serenity/commit/ccb83744342
Pull-request: https://github.com/SerenityOS/serenity/pull/11488
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibCore/System.cpp

@@ -20,6 +20,10 @@
 #include <termios.h>
 #include <unistd.h>
 
+#ifdef __serenity__
+#    include <serenity.h>
+#endif
+
 #define HANDLE_SYSCALL_RETURN_VALUE(syscall_name, rc, success_value) \
     if ((rc) < 0) {                                                  \
         return Error::from_syscall(syscall_name, rc);                \
@@ -125,6 +129,12 @@ ErrorOr<long> ptrace(int request, pid_t tid, void* address, void* data)
         return Error::from_syscall("ptrace"sv, -errno);
     return rc;
 }
+
+ErrorOr<void> disown(pid_t pid)
+{
+    int rc = ::disown(pid);
+    HANDLE_SYSCALL_RETURN_VALUE("disown", rc, {});
+}
 #endif
 
 #ifndef AK_OS_BSD_GENERIC

Userland/Libraries/LibCore/System.h

@@ -41,6 +41,7 @@ ErrorOr<void> ptrace_peekbuf(pid_t tid, void const* tracee_addr, Bytes destinati
 ErrorOr<void> setgroups(Span<gid_t const>);
 ErrorOr<void> mount(int source_fd, StringView target, StringView fs_type, int flags);
 ErrorOr<long> ptrace(int request, pid_t tid, void* address, void* data);
+ErrorOr<void> disown(pid_t pid);
 #endif
 
 #ifndef AK_OS_BSD_GENERIC