samples: add Terra samples

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

samples/Terra/vec.t

@@ -0,0 +1,27 @@
+
+terra foo(a : double)
+    var v0 : vector(double,3) = a
+    var v1 : vector(int,3) = 4
+    var v2 = v0 / v1
+    var v3 = (v0 <= v1) or (v1 >= v0)
+    var ptr = [&double](&v2)
+    return v3[0] or v3[1] or v3[2]
+    --return ptr[0] + ptr[1] + ptr[2]
+end
+
+
+N = 64
+terra addsomevecs(a : vector(double,N), b : vector(double,N), c : vector(double,N) )
+	return (a + b) / c
+end
+
+
+terra foo2(a : double, b : double)
+	var c = addsomevecs(a,b,b)
+	return c[0] + c[1]
+end
+
+local test = require("test")
+
+test.eq(foo(3), true)
+test.eq(foo2(3,4), 3.5)