glibc: avoid poisoning the cache namespace with zig lib dir
In glibc.zig, there were a few instances where the zig lib dir path name
incorrectly made its way into the cache namespace for various build
artifacts, resulting in unnecessary rebuilds of glibc.
Closes #13619
8ff9284c46Andrew Kelley committed on 12/15/2022, 5:07:53 AMparentc2f5848