+# FIXME: Things like :c-stack-grows-..., etc, should be
+# *derived-target-features* or equivalent, so that there was a nicer
+# way to specify them then sprinkling them in this file. They should
+# still be tweakable by advanced users, though, but probably not
+# appear in *features* of target. #!+/- should be adjusted to take
+# them in account as well. At minimum the nicer specification stuff,
+# though:
+#
+# (define-feature :dlopen (features)
+# (union '(:bsd :linux :darwin :sunos) features))
+#
+# (define-feature :c-stack-grows-downwards-not-upwards (features)
+# (member :x86 features))
+