Fixes#49071
On ld.gold, we produce broken executables when linking with the Musl
libc. This appears to be a known bug when using ld.gold and Musl. This
thread describes the workaround as enabling PIE when using ld.gold and
Musl:
https://www.openwall.com/lists/musl/2015/05/01/5
By default we don’t enable PIE to avoid breaking things. But in the
Musl case we are breaking things by not enabling PIE. So this adds a
special case for defaultHardeningFlags which keeps the pie hardening
for everything. Any packages that break with PIE can add the pie flag
to disableHardeningFlags array (a no-op for now on anything but Musl).
6d531f3541