samples: add Terra samples

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

samples/Terra/let1.t

@@ -0,0 +1,15 @@
+
+
+terra foo()
+	return (1),(2)
+end
+
+terra bar()
+	var c = [quote var a = 3 in a end]
+	var d = 5
+	c = c + 10
+	return [quote var a = 3 in [quote var b = 4 in a + b + c + d end] end]
+end
+local test = require("test")
+test.meq({1,2},foo())
+assert(25 == bar())