Feature Request: Allow for precompile_file to be passed to PackageCompiler

[schlichtanders]

Hi there,
I've been using PackageCompiler a lot and would like to use JuliaC.jl instead for future maintainability and the --trim option.

However it seems that JuliaC.jl does not support a precompile_file option yet. That would be highly apprecaited as package precompilation is still limited, e.g. for Plotting and others. Too many functions are invalidated in runtime so that the standard precompilation actually does not work. Baking it into a packagecompile image on the other hand actually is able to improve the speedup even further from my experience.

[CrispyCow]

I'd like to second this request. I have been playing around with both PacakgeCompiler and JuliaC for my project. I find JuliaC much easier to use, but I still get a significantly faster load using PackageCompiler with a precompile file. Exposing the 'precompile_statements_file' from PackageCompiler would be perfect.