llvmpipe/draw: drop variant number from function names.

llvmpipe/draw: drop variant number from function names.

When we use an object cache for the MCJIT we can have identical
cache entries from the same shader variant in different shaders,
but the JIT objcache uses the function name to relink things,
so it has to be consistent. Just drop the variants from the
function names.

Note the modules still have the variant info.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5049>