make-derivation: enable pie hardening with musl

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).

pkgs/stdenv/generic/make-derivation.nix

@@ -93,7 +93,9 @@ rec {
                                       ++ depsTargetTarget ++ depsTargetTargetPropagated) == 0;
       runtimeSensativeIfFixedOutput = fixedOutputDrv -> !noNonNativeDeps;
       supportedHardeningFlags = [ "fortify" "stackprotector" "pie" "pic" "strictoverflow" "format" "relro" "bindnow" ];
-      defaultHardeningFlags = lib.remove "pie" supportedHardeningFlags;
+      defaultHardeningFlags = if stdenv.targetPlatform.isMusl
+                              then supportedHardeningFlags
+                              else lib.remove "pie" supportedHardeningFlags;
       enabledHardeningOptions =
         if builtins.elem "all" hardeningDisable
         then []