Import the attached Blend SM2.shader in Unity 4.x. It will work fine. Import it in Unity 5.0 and you will get the following compilation error:
"Arithmetic instruction limit of 64 exceeded; 65 arithmetic instructions needed to compile program"

There is a workaround to make the errors go away, by adding "#pragma target 3.0" to the appropriate place in the shader file, but that has its own drawbacks.