In Emacs 29, text pasted from the clipboard on macOS will be truncated if containing NULs.

Reproduction: copy text with NUL in the middle from Emacs 28 (or any other application), and paste into Emacs 29.

This was probably caused by 7e3c2b553f, where construction of a Lisp string was changed from make_string to build_string.

Suggested patch attached. If valid, would it qualify for emacs-29?