sys-libs/glibc: remove libcrypt in favor of libxcrypt

Glibc deprecated libcrypt and will remove it in the future.
Until then all distros should move to alternatives like
libxcrypt which Gentoo migrated too.

This moves CrOS to libxcrypt as well by enabling it's
"system" use flag and removing the glibc "crypt" flag,
so all glibc's including cross-* versions will be built
without libcrypt.

libxcrypt is binary compatible with glibc libcrypt.

BUG=b:187795307
TEST=Local builds with cross-*; emerge-eve/kevin; CQ.

Cq-Depend: chromium:3620893, chromium:3620694, chromium:3645212
Change-Id: I10110a12775bd8110b9bd839153106d39acf82e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/3652290
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
8 files changed