samples: add Terra samples

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

samples/Terra/simplevec.t

@@ -0,0 +1,12 @@
+
+terra sum(input : &float, N : int)
+	var acc : vector(float,4) = vector(0.f,0.f,0.f,0.f)
+	for i = 0,N,4 do
+		--cast the floats to float4s and load
+		var entry = @[&vector(float,4)](input + i)
+		acc = acc + entry
+	end
+	return acc[0] + acc[1] + acc[2] + acc[3]
+end
+
+sum:disas()