added use statement for stdlib_bitsets

Author: degawa

src/stdlib_sorting.fypp

@@ -129,6 +129,9 @@ module stdlib_sorting
     use stdlib_string_type, only: string_type, assignment(=), operator(>), &
         operator(>=), operator(<), operator(<=)
 
+    use stdlib_bitsets, only: bitset_64, bitset_large, &
+        assignment(=), operator(>), operator(>=),operator(<),operator(<=)
+
     implicit none
     private