samples: add Terra samples

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

samples/Terra/symbolvar3.t

@@ -0,0 +1,16 @@
+
+
+local a = symbol()
+
+local q = quote 
+	var [a] = 2
+	[a] = [a] + 1
+end
+
+terra foo()
+	q
+	return [a]
+end
+
+local test = require("test")
+test.eq(3,foo())