One of these left after #34266 is

build/pkgs/flint/patches/0001-flint.h-On-GCC-4.9-do-not-use-_Thread_local.patch

there are more (see the branch)

CC: @mkoeppe

Component: build

Author: Dima Pasechnik

Branch/Commit: fb783e0

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/34682