wined3d: Take predication tokens into account.

wined3d: Take predication tokens into account.

Each instruction can have a predication token. Account for it in the
trace pass, register count pass, and store it in the SHADER_OPCODE_ARG
structure for generation. MSDN claims the token is at the end of the
instruction, but that's not true - testing a demo, which lets me
manipulate the shader shows the predication token is the first source
token immediately following the destination token.