bsd-user mmap and exec branches from gsoc This pull request represents the mmap and exec changes from Karim Taha for his GSoC project. They represent all the mmap and exec related system calls and get bsd-user to the point that a dynamic hello-world works (at least for armv7). There are a couple of patch check errors, but they are the lessor evil: I made purposely bad style choices to ensure all the commits compiled (and i undid the style choices in subsequent commits). I pushed an earlier version to gitlab, and all but the riscv64 pipelines were green. Since bsd-user doesn't change anything related to ricsv64 (there's no support in qemu-project repo, though we do have it in the bsd-user fork: coming soon). I think this is good to go. https://gitlab.com/bsdimp/qemu.git Warner