Add ld.gold and ld.lld compiler wrapper (#25626)

The gcc compiler can be configured to use `ld.gold` by default. It will
then call `ld.gold` explicitly when linking. When so, spack need to have
a ld.gold wrapper in PATH to inject rpaths link flags etc...

Also I wouldn't be surprised to see some package calling `ld.gold`
directly.

As for ld.gold, the argument could be made that we want to support any
package that could call ld.lld.

.gitignore

@@ -132,6 +132,7 @@ celerybeat.pid
 .env
 .venv
 env/
+!/lib/spack/env
 venv/
 ENV/
 env.bak/