realpath is a GNUUtils package that is not available on recent OSX
TEST=Build on OSX systems without GNUutils + zsh
Change-Id: I573855b93a08e1746e0bb214be28b4a3ea8264ca
* Enables -gsplit-dwarf for both LLVM and NPCOMP, reducing the occurrence of the ~GB scale binaries.
* CMake shared linking seems incompatible with this, so shared objects are still "too big" but there are few of them.
* Reduces disk thrash on clean/install of everything.
* Forks a subset of my shell functions into docker_shell_funcs.sh, specifically needed to create docker images that run as yourself.
* Extends the readme with the three command bootstrap to get a dev container running.
* Step by step instructions for configuring VSCode for Intellisense in either npcomp or LLVM.
* Changes LLVM config options to enable tests. This setup is now suitable for upstream changes as well without rebuilding.
* Includes pybind11 directly (for some reason using the pytorch helper header for this depends on a source file not in the image).
* Installs nnpack into the image.
* Installs new-clang and LLD and configures environment to use it (otherwise, link time is terrible).
* Fixes a gcc compile error (in the off chance you build with default gcc compiler).
* Tests are failing based on some dialect registration stuff that must not have been factored correctly. Will followup with a fix.