missing libatomic for powerpc etc

[Makoto Fujiwara <makoto%ki.nu@localhost>]

By reading this report by he@ at the part of R-* missing libatomic,
  http://mail-index.netbsd.org/pkgsrc-bulk/2023/04/15/msg023669.html

I would like to apply attached patch, does it make sense ?
-- 
Makoto Fujiwara
mef%NetBSD.org@localhost
makoto%if.t.u-tokyo.ac.jp@localhost
Key fingerprint = 0BFA FAEB EAD1 90BA 7498  8F85 6809 9E0B B7EF A12E
----
pkgsrc freshness:
http://www.ki.nu/~makoto/pkgsrc/check-update/00_Summary.html

Index: math/R/Makefile.extension
===================================================================
RCS file: /cvsroot/pkgsrc/math/R/Makefile.extension,v
retrieving revision 1.28
diff -u -r1.28 Makefile.extension
--- math/R/Makefile.extension	23 Mar 2022 21:16:44 -0000	1.28
+++ math/R/Makefile.extension	15 Apr 2023 22:30:55 -0000
@@ -76,4 +76,5 @@
 DEINSTALL_TEMPLATES+=	../../math/R/files/pkg-index.tmpl
 CHECK_FILES_SKIP+=	${PREFIX}/${R_LIB}/R.css
 
+.include "../../mk/atomic64.mk"
 .include "../../math/R/buildlink3.mk"