feat(co_all): make impure elemental

Author: rouson

src/sourcery/user_defined_collectives_m.f90

@@ -12,7 +12,7 @@ module user_defined_collectives_m
 
   interface
 
-    module subroutine co_all(boolean)
+    impure elemental module subroutine co_all(boolean)
       !! If any image in a team calls this subroutine, then every image in the 
       !! the same team must call this subroutine.  This subroutine sets the
       !! "boolean" argument .true. if it is true in all participating images