Incorrect Code Generation for anonymous functions

[avik-pal]

(args...) -> copy(l.weight) gets rewritten as

args...->begin
    #= none:59 =#
    copy(l.weight)
end

which causes a syntax error.

Example File where this occurs: https://github.com/LuxDL/Lux.jl/blob/f34e95d17608fd1d8610792b500db091d615361c/ext/LuxFluxTransformExt.jl

[cjdoris]

Thanks - essentially a dup of #8 but I'll ensure both issues are covered by tests.