samples: add Terra samples

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

samples/Terra/splitprimary.t

@@ -0,0 +1,19 @@
+r = 1
+local function foo(a)
+	r = a
+	return r
+end
+local b = foo(1)
+(foo)(3)
+assert(b + r == 4)
+
+terra testescapes()
+	var a  = [4]
+	[ quote 
+		a = a + 1
+	  end
+	]
+	return [ `&a ][0]
+end
+
+assert(testescapes() == 5)