We need 64-bit lib path.

--- grep-3.4/m4/lib-prefix.m4.old	2020-01-03 09:10:56.037530527 +0000
+++ grep-3.4/m4/lib-prefix.m4	2020-01-03 09:11:00.143439526 +0000
@@ -235,7 +235,7 @@ changequote([,])dnl
     [acl_cv_libdirstems],
     [dnl Try 'lib' first, because that's the default for libdir in GNU, see
      dnl <https://www.gnu.org/prep/standards/html_node/Directory-Variables.html>.
-     acl_libdirstem=lib
+     acl_libdirstem=lib/64
      acl_libdirstem2=
      acl_libdirstem3=
      case "$host_os" in