Remove getfield_elim_pass, try CI.

[tshort]

To try to get latest CI to pass, I tested a few changes using the beta version of Julia v1.8. I commented out the definition of optimize. That removes the call to optimize!. Next I had to change the ccall to jl_create_native following GPUCompiler:

        native_code = if VERSION >= v"1.8.0-DEV.661"
            ccall(:jl_create_native, Ptr{Cvoid},
                  (Vector{MethodInstance}, Ptr{Base.CodegenParams}, Cint),
                  [ssg.entry], Ref(params), #=extern policy=# 1)
        else
            ccall(:jl_create_native, Ptr{Cvoid},
                  (Vector{MethodInstance}, Base.CodegenParams, Cint),
                  [ssg.entry], params, #=extern policy=# 1)
        end

After these changes, tests pass until a failure in the LoopVectorization tests.