Add base for GnuCobol version

COBOL/Gnu/.gitignore

@@ -0,0 +1,3 @@
+in-items
+items
+GildedRose.so

COBOL/Gnu/GildedRose.cbl

@@ -0,0 +1,76 @@
+program-id. GildedRose as "GildedRose".
+
+environment division.
+
+input-output section.
+
+file-control.
+    select in-items assign 'in-items'.
+    select items assign 'items'.
+
+data division.
+file section.
+   fd in-items.
+   01 in-item pic x(58).
+   fd items.
+   01 item.
+      02 sell-in pic 9(4).
+      02 quality pic 9(4).
+      02 name pic x(50).
+
+working-storage section.
+procedure division.
+    open input in-items output items.
+start-lable.
+    read in-items end go to end-lable.
+        move in-item to item.
+        if name not equal "Aged Brie" and name not equal "Backstage passes to a TAFKAL80ETC concert"
+            if quality > 0
+                if name not equal to "Sulfuras, Hand of Ragnaros"
+                    compute quality = quality - 1
+                end-if       
+            end-if
+        else
+            if quality < 50
+                compute quality = quality + 1
+                if name equals "Backstage passes to a TAFKAL80ETC concert"
+                    if sell-in < 11
+                        if quality < 50
+                            compute quality = quality + 1
+                        end-if
+                    end-if
+                    if sell-in < 6
+                        if quality < 50
+                            compute quality = quality + 1
+                        end-if
+                    end-if
+                end-if
+            end-if
+        end-if
+        if name not equal "Sulfuras, Hand of Ragnaros"
+            compute sell-in = sell-in - 1
+        end-if
+        if sell-in < 0
+            if name is not equal to "Aged Brie"
+                if name is not equal to "Backstage passes to a TAFKAL80ETC concert"
+                    if quality > 0
+                        if name is equal to "Sulfuras, Hand of Ragnaros"
+                            compute quality = quality - 1
+                        end-if
+                    end-if
+                else
+                    compute quality = quality - quality
+                end-if
+            else
+                if quality < 50
+                    compute quality = quality + 1
+                end-if
+            end-if
+        end-if
+        write item.
+    go to start-lable.
+end-lable.
+    close items.
+goback.
+
+end program GildedRose.

COBOL/Gnu/build.sh

@@ -0,0 +1 @@
+cobc --free --std=mf -O GildedRose.cbl

COBOL/Gnu/run.sh

@@ -0,0 +1,2 @@
+touch in-items
+cobcrun GildedRose