[libc] Fix build when -DBUILD_SHARED_LIBS=On

Reviewers: gchatelet, sivachandra

Reviewed By: gchatelet, sivachandra

Subscribers: libc-commits, mgorny, MaskRay, tschuett

Differential Revision: https://reviews.llvm.org/D75136

GitOrigin-RevId: 805f5836d1bbd03dcc9de78881bd81dc8cb09cc4
2 files changed