clock_monotonic_nsec() declared a hand-rolled `extern "C" fn
libc_clock_gettime` plus a private timespec/CLOCK_MONOTONIC — but relibc
exports `clock_gettime`, not `libc_clock_gettime`, so the cross link failed:
undefined reference to `libc_clock_gettime'
Use the libc crate's binding (libc::clock_gettime / libc::CLOCK_MONOTONIC /
libc::timespec), already a dependency and used throughout this file. Removes
the bespoke extern block, struct, and const.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
vasilito
8e7aea9fc5