samples: add Terra samples

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

samples/Terra/blockescape.t

@@ -0,0 +1,23 @@
+terra foo() 
+    var c = 3 
+    escape 
+        local a = 1
+        for i = 1,10 do
+            emit quote c = c + a end 
+        end
+    end 
+    return c 
+end
+
+assert(foo() == 13)
+
+terra foo2()
+    return escape emit(1) end
+end
+
+assert(1 == foo2())
+
+a = terralib.newlist()
+a:insert quote
+    foo()
+end