samples: add Terra samples

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

samples/Terra/macro.t

@@ -0,0 +1,50 @@
+
+local bar = terralib.internalmacro(function(ctx,tree,typ)
+	return terralib.newtree(typ.tree, { kind = terralib.kinds.literal, type = double, value = 4.0 })
+	
+end)
+
+local bar2 = macro(function(typ)
+	return typ
+	
+end)
+
+
+local bar3 = macro(function(a,b)
+    return {a.tree,b.tree}
+end)
+
+terra up(v : &int)
+    @v = @v + 1
+end
+
+local bar4 = macro(function()
+    local terra myfn()
+        return 42
+    end
+    return myfn
+end)
+
+moo = global(int,3)
+
+local bar4 = macro(function()
+    local terra myfn()
+        return 42
+    end
+    return myfn
+end)
+
+local bar5 = macro(function()
+    return moo
+end)
+
+terra foo() : int
+	var a : int = bar(int,int16,int32)
+	bar2(a) = bar2(a) + 5
+	bar3(up(&a),up(&a))
+	bar5() = bar5() + 1
+	return a + bar4()() + moo
+end
+
+local test = require("test")
+test.eq(57,foo())