meta: replace cmake mono-build system with a custom build co-ordinator

every system component now has its own self-contained build system, and a
seed file describing the component and its build system and dependencies.

a new tool, meadow, collects and uses these seed files to build the
components into a full system. meadow also manages the target system root
and a host prefix where toolchain tools are installed to.

the build system has also been updated to use a new $ARCH-rosetta-gcc
compiler, and the patches files necessary to build it have been
added to toolchain/cross-compiler.

arch/x86_64/x86_64-pc.platform

@@ -0,0 +1,19 @@
+[platform]
+name = 'x86_64-pc'
+arch = 'x86_64'
+
+[cmake]
+module_paths = [ '.' ]
+system_name = 'Rosetta'
+toolchain_file = 'Platform/Rosetta.cmake'
+
+[extension]
+commands = [
+	'command/run-kernel.command',
+]
+
+seeds = [
+	'cdrom.seed'
+]
+
+# vim: ft=toml