Adjust to upcoming effects change

This is for JuliaLang/julia#43852.

Probably hold off on merging until the review phase is through,
but the PR is here for people who want to work on the branch
and need Revise to work.

src/optimize.jl

@@ -272,7 +272,8 @@ function build_compiled_call!(stmt::Expr, fcall, code, idx, nargs::Int, sparams:
         # f(x, y) =  ccall(:jl_value_ptr, Ptr{Cvoid}, (Float32,Any), x, y)
         # @code_lowered f(2, 3)
         args = []
-        for (atype, arg) in zip(ArgType, stmt.args[6:6+nargs-1])
+        argstart = isdefined(Base, Symbol("@assume_effects")) ? 7 : 6
+        for (atype, arg) in zip(ArgType, stmt.args[argstart:argstart+nargs-1])
             if atype === Any
                 push!(args, arg)
             else