The regmask currently being used is wrong - 0x1FFF includes the high
two bits of the register type.

The _dw modifier needs to specify a component swizzle, just like the
_dz currently does.

- else, endif, break take 0 parameters [not 2]
- if, rep take 1 parameter [not 2]
- breakp takes 1 parameter [not 2]
- move all flow control instructions in one place
- sync software shaders signatures with this

Use correctly the GetOpenFileName function.
Use _lcreat instead of _lopen to create a new file.

Use get_parameter to read the three parameters to RegisterOCX.
Remove the ERRs and TRACEs now that we return the HRESULT.