bloaty: fix build on ppc32 and armv6 (use libatomic) + nocross

According to CI, this currently fails on all cross archs because
of failure to use vendored protobuf.

srcpkgs/bloaty/template

@@ -11,15 +11,27 @@ license="Apache-2.0"
 homepage="https://github.com/google/bloaty"
 distfiles="https://github.com/google/bloaty/releases/download/v${version}/bloaty-${version}.tar.bz2"
 checksum=e1cf9830ba6c455218fdb50e7a8554ff256da749878acfaf77c032140d7ddde0
+nocross="fails to use vendored protobuf"
 
 case "$XBPS_TARGET_MACHINE" in
-	armv6*) broken="undefined reference to __atomic_fetch_add_8'" ;;
+	ppc64*) ;;
+	armv6*|ppc*) makedepends+=" libatomic-devel";;
 esac
 
 if [ "$CROSS_BUILD" ]; then
 	hostmakedepends+=" protobuf"
 fi
 
+post_extract() {
+	case "$XBPS_TARGET_MACHINE" in
+		ppc64*) ;;
+		armv6*|ppc*)
+			echo 'target_link_libraries(libprotobuf atomic)' >> \
+				third_party/protobuf/cmake/libprotobuf.cmake
+		;;
+	esac
+}
+
 do_install() {
 	vbin build/bloaty
 }