Restore the libiberty component of commit 50ad1254d5030d0804cbf89c758359ae202e8d55.

This commit has not yet been applied to the master sources in the gcc repository.
It was submitted here: https://gcc.gnu.org/pipermail/gcc-patches/2021-July/574405.html
The commit allows options to be set for the AR and RANLIB programs used when building libiberty, which in turn allows building with LTO enabled.
4 files changed