samples: add Terra samples

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

samples/Terra/rvaluerecv.t

@@ -0,0 +1,30 @@
+struct A { a : int }
+
+terra A:foo() 
+    self.a = self.a + 1
+    return self.a
+end
+
+terra A.methods.foo2(self : A) 
+    self.a = self.a + 1
+    return self.a
+end
+
+
+mya = global(A)
+mya:set({0})
+
+terra geta()
+    return mya
+end
+
+terra bar()
+    var v0 = mya.a
+    var v1 = geta():foo()
+    var v2 = mya.a
+    var v3 = geta():foo2()
+    var v4 = mya.a
+    return v0,v1,v2,v3,v4
+end
+test = require("test")
+test.meq({0,1,0,1,0},bar())