winedbg: When filling an imagehlp frame information, also do the stack field, it's used on x86-64 platforms.

wineboot: Start an additional 32-bit instance of rundll32 on 64-bit platforms to do the Wow64-specific setup.

Now the shader assembler is structurally complete and it correctly
assembles one trivial shader program.

Currently it only accepts a minimal subset of the syntax (e.g. just an
instruction and two register types supported) and doesn't produce any
real output (i.e. shader bytecode).