This avoids the double search for a pixel shader. The pixel shader
compilation parameter structure is recorded in the GLSL program
hashmap, together with the WineD3D pixel shader.

The dx7 sdk demos need this.

Some stateblock parameters have to be compiled into the GL pixel
shader code, like lines for pixelformat fixups. This leads to problems
when applications switch those settings, requiring a recompilation of
the shader. This patch enables wined3d to have multiple GL shaders for
a D3D shader(pixel shaders only so far) to handle this more
efficiently.

This was suggested by Ivan quite a while ago, and we need it to better
handle conflicting texture format corrections and similar stateblock
value changes which until now required a recompilation of the entire
shader

A number of considerations contribute to this:

1) The shader backend knows best which shader(s) it needs. GLSL needs
both, arb only one
2) The shader backend may pass some parameters to the compilation
code(e.g. which pixel format fixup to use)
3) The structures used in (2) are different in vs and ps, so a
baseshader::Compile won't work
4) The structures in (2) are wined3d-private structures, so
having a public method in the vtable won't work(its a bad idea
anyway).

Also rename it to virtual_handle_fault for consistency.