In libc_r, if _FDLOCKS_ENABLED is not defined, there is no guarantee
in many of the sycall wrappers that _thread_fd_table[fd] is
initialized. This causes problems for programs that pass in file
descriptors and execve() another program; when the exec'ed program
tries to do an fcntl() or other syscall on the passed-in fd, it fails.
Add calls to initialize the FD table entry for _thread_fd_lock and
_thread_fd_lock_debug.
Submitted by: Peter S. Housel <housel@acm.org>
f39105fa50