samples: add Terra samples

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

samples/Terra/localenv.t

@@ -0,0 +1,46 @@
+
+local a = 4
+b = 3
+local terra foo()
+	return a + b
+end
+local terra bar()
+	return foo()
+end
+local test = require("test")
+
+test.eq(foo(),7)
+test.eq(bar(),7)
+
+terra nested()
+	return [ (function(a) return a + b end)(8) ]
+end
+terra nested2()
+	return [ a + b ]
+end
+local c = {}
+local d = {}
+local vv = {}
+local b = 3
+local e = 8
+g = 1
+local dd = 8
+ aa = global(10)
+terra nested3()
+	var luav = 8
+	return [ (function()
+		local b = 5
+		function c.b() return 7 end
+		local f = 7
+		vv.bb = global(aa:get())
+		terra d.c() return e + f + g + vv.bb + [ `dd ] end
+		return b + a
+	end)() ]
+end
+
+test.eq(nested(),11)
+
+test.eq(nested2(),7)
+test.eq(nested3(),9)
+test.eq(c.b(),7)
+test.eq(d.c(),34)