Genode platform library for Nim

This is a Nim library for interacting with the Genode OS.

Simply adding import genode to a project is also sufficient for passing the necessary compiler flags thru the toolchain.

A pattern for use with Nimble:

...
srcDir = "src"
bin    = @["foo"]

requires "nim >= 1.0.0", "genode"

task genode, "Build for Genode":
  exec "nim cpp --os:genode -d:posix -o:foo.genode src/foo"

This adds a task for building a Genode binary invoked by calling nimble genode through the shell. The compilier will invoke pkg-config and thus needs PKG_CONFIG_PATH set to point at the pkgconfig files supplied with a Genode SDK, so the command to use is probably closer to PKG_CONFIG_PATH="/opt/genode-sdk-x86_64/pkgconfig" nimble genode.

See https://github.com/ehmry/genode/releases/ for a compatible SDK.