* module/ice-9/boot-9.scm (%cond-expand-features): Add new features.
* doc/ref/srfi-modules.texi (SRFI-0): Document new features.
@example
guile
-guile-2 ;; starting from Guile 2.x
-guile-2.2 ;; starting from Guile 2.2
-guile-3.0 ;; starting from Guile 3.0
+guile-2 ;; starting from Guile 2.x
+guile-2.2 ;; starting from Guile 2.2
+guile-3 ;; starting from Guile 3.x
+guile-3.0 ;; starting from Guile 3.0
r5rs
+r6rs
+r7rs
+exact-closed ieee-float full-unicode ratios ;; R7RS features
srfi-0
srfi-4
srfi-6
'(guile
guile-2
guile-2.2
+ guile-3
+ guile-3.0
r5rs
+ r6rs
+ r7rs
+ exact-closed ieee-float full-unicode ratios ;; R7RS features.
srfi-0 ;; cond-expand itself
srfi-4 ;; homogeneous numeric vectors
srfi-6 ;; string ports