darwin hints querylocale race in earlier darwins?

hints/darwin.sh

@@ -363,6 +363,8 @@ esac
 
 # Darwin's querylocale() has races
 ccflags="$ccflags -DNO_THREAD_SAFE_QUERYLOCALE"
+# XXX
+ccflags="$ccflags -DNO_POSIX_2008_LOCALE"
 
 # But it doesn't much matter because the whole implementation has bugs [GH
 # #21556]
@@ -536,3 +538,5 @@ d_mkostemp=undef
 # Apparently the MACH-O format can't support _Thread_local in shared objects,
 # but clang isn't wise to this, so our probe works but the build fails...
 d_thread_local=undef
+
+d_querylocale=undef