samples: add Terra samples

source: https://github.com/zdevito/terra/tree/master/tests

samples/Terra/struct.t

@@ -0,0 +1,50 @@
+--the zero line
+struct A { b : B } and
+struct B {a : int, b : int}
+
+terra bar(a : B)
+    a.a = a.a + 1
+    return a,3
+end
+
+terra foo()
+    var a : B
+    a.a = 4;
+    --(bar(a)).a = 3, TODO: why is the offset == 0 for this value?
+    var c,d = bar(a)
+    return c.a + a.a + d
+end
+
+
+terra baz(a : &B)
+    a.a = 1
+    a.b = 2
+    return a.a
+end
+
+
+terra foo2()
+    var a : B
+    var d = baz(&a)
+    return a.a + a.b + d
+end
+local test = require("test")
+
+test.eq(foo(),12)
+test.eq(foo2(),4)
+
+
+local C = tuple(int, int)
+
+local D = tuple(int, int)
+
+terra anon()
+    var c : C
+    c._0 = 3
+    c._1 = 4
+    var d : D = c
+    --var b : B = d
+    return d._0 + d._1
+end
+
+test.eq(anon(),7)