mesa: Improve static error checking of arrays sized by MESA_SHADER_TYPES.

mesa: Improve static error checking of arrays sized by MESA_SHADER_TYPES.

This patch replaces the following pattern:

    foo bar[MESA_SHADER_TYPES] = {
       ...
    };

With:

    foo bar[] = {
       ...
    };
    STATIC_ASSERT(Elements(bar) == MESA_SHADER_TYPES);

This way, when a new shader type is added in a future version of Mesa,
we will get a compile error to remind us that the array needs to be
updated.

Reviewed-by: Brian Paul <brianp@vmware.com>