vkd3d-shader/tpf: Emit constant values inline.

How much of an heresy is this thing?

It has a negative diff count, you can't approve this! Also, it causes the HLSL compiler to emit slightly shorter and more readable TPF code. And using fewer registers.

I guess something similar should be doable for D3DBC too, though it requires some previous refactoring to have a single place where to intercept constant registers susceptible to be inlined.