Add code for lecture 6

Signed-off-by: jmug <u.g.a.mariano@gmail.com>

lec06/code/dune

@@ -0,0 +1,50 @@
+(env
+ (dev
+  (flags
+   (:standard -w "+a-4-7-9-27-29-30-32..42-44-45-48-50-60-66..70")
+   ))) 
+
+(library
+ (name ir_by_hand)
+ (modules ir_by_hand))
+
+(library
+ (name ir1)
+ (modules ir1))
+
+(library
+ (name ir2)
+ (modules ir2))
+
+(library
+ (name ir3)
+ (modules ir3))
+
+ (library
+ (name ir4)
+ (modules ir4))
+
+(library
+ (name i5)
+ (modules ir5))
+
+(executable
+ (public_name main1)
+ (name main1)
+ (modules main1)
+ (libraries ir1)
+ (promote (until-clean)))
+
+(executable
+ (public_name main2)
+ (name main2)
+ (modules main2)
+ (libraries ir2)
+ (promote (until-clean)))
+
+(executable
+ (public_name main3)
+ (name main3)
+ (modules main3)
+ (libraries ir3)
+ (promote (until-clean)))