Rollup merge of rust-lang#148126 - hax0kartik:vx-fix-148125, r=Mark-Simulacrum

Fix rust stdlib build failing for VxWorks

Fixes rust-lang#148125.

O_NOFOLLOW is not supported on VxWorks. All the other defines/functions have been added to libc(rust-lang/libc@0cd5032)

Author: Zalathar