samples: add Terra samples

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

samples/Terra/includetwice.t

@@ -0,0 +1,21 @@
+
+
+local C1 = terralib.includecstring [[
+	typedef struct { int a; } A;
+	int geta(A* a) { return a->a; }
+]]
+local C2 = terralib.includecstring [[
+	typedef struct { int a; } A;
+	void seta(A* a, int v) { a->a = v; }
+]]
+
+assert(C1.A == C2.A)
+
+
+terra usethem()
+	var a = C1.A { 1 }
+	C2.seta(&a,C1.geta(&a) + 3)
+	return a.a
+end
+
+assert(usethem() == 4)