app-arch/xz-utils: revbump to propagate PGO fix, backport to 5.6.4 too

* Revbump to propagate PGO fix (see 7ab9960e98)
  as we don't expect a new release soon.
* Backport 5.8.1 ebuild changes to 5.6.4.

Signed-off-by: Sam James <sam@gentoo.org>

app-arch/xz-utils/xz-utils-5.6.4-r2.ebuild

@@ -6,7 +6,7 @@
 
 EAPI=8
 
-inherit libtool multilib multilib-minimal preserve-libs toolchain-funcs
+inherit dot-a flag-o-matic libtool multilib multilib-minimal preserve-libs toolchain-funcs
 
 if [[ ${PV} == 9999 ]] ; then
 	# Per tukaani.org, git.tukaani.org is a mirror of github and
@@ -71,6 +71,11 @@ src_prepare() {
 	fi
 }
 
+src_configure() {
+	use static-libs && lto-guarantee-fat
+	multilib-minimal_src_configure
+}
+
 multilib_src_configure() {
 	local myconf=(
 		--enable-threads
@@ -113,8 +118,11 @@ multilib_src_configure() {
 }
 
 multilib_src_compile() {
-	local pgo_generate_flags=$(usev pgo "-fprofile-update=atomic -fprofile-dir=${T}/${ABI}-pgo -fprofile-generate=${T}/${ABI}-pgo")
-	local pgo_use_flags=$(usev pgo "-fprofile-use=${T}/${ABI}-pgo -fprofile-dir=${T}/${ABI}-pgo")
+	# -fprofile-partial-training because upstream note the test suite isn't super comprehensive
+	# TODO: revisit that now we have the tar/xz loop below?
+	# See https://documentation.suse.com/sbp/all/html/SBP-GCC-10/index.html#sec-gcc10-pgo
+	local pgo_generate_flags=$(usev pgo "-fprofile-update=atomic -fprofile-dir=${T}/${ABI}-pgo -fprofile-generate=${T}/${ABI}-pgo $(test-flags-CC -fprofile-partial-training)")
+	local pgo_use_flags=$(usev pgo "-fprofile-use=${T}/${ABI}-pgo -fprofile-dir=${T}/${ABI}-pgo $(test-flags-CC -fprofile-partial-training)")
 
 	emake CFLAGS="${CFLAGS} ${pgo_generate_flags}"
 
@@ -189,6 +197,8 @@ multilib_src_install() {
 }
 
 multilib_src_install_all() {
+	strip-lto-bytecode
+
 	find "${ED}" -type f -name '*.la' -delete || die
 
 	if use doc ; then