sys-fs/progsreiserfs: mark as LTO-unsafe on musl

It fails with linker errors due to including a code copy of a manky old
libintl.

Happens because for some inexplicable reason, packages which genuinely
need the full power and flexibility of GNU libintl, can only rely on
dev-libs/libintl on *non* linux operating systems, even though it was
very much intended upstream to be useful and usable on musl systems.

glibc, obviously, works fine.

Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>

sys-fs/progsreiserfs/progsreiserfs-0.3.1_rc8-r1.ebuild

@@ -39,6 +39,9 @@ src_prepare() {
 
 src_configure() {
 	filter-lfs-flags
+	# bundled libintl gets used because dev-libs/libintl isn't an option on musl
+	# and fails to LTO: undefined reference to `__argz_count'
+	use elibc_glibc && filter-lto
 
 	econf \
 		$(use_enable static-libs static) \