Initial data commit

Task/String-prepend/360-Assembly/string-prepend.360

@@ -0,0 +1,18 @@
+*        String prepend - 14/04/2020
+PREPEND  CSECT
+         USING  PREPEND,13         base register
+         B      72(15)             skip savearea
+         DC     17F'0'             savearea
+         SAVE   (14,12)            save previous context
+         ST     13,4(15)           link backward
+         ST     15,8(13)           link forward
+         LR     13,15              set addressability
+         MVC    C+L'B(L'A),A       c=a
+         MVC    C(L'B),B           c=b+c  (prepend)
+         XPRNT  C,L'C              print buffer
+         L      13,4(0,13)         restore previous savearea pointer
+         RETURN (14,12),RC=0       restore registers from calling sav
+A        DC     C'world!'          a
+B        DC     C'Hello '          b
+C        DC     CL80' '            c
+         END    PREPEND