cross-compile support.
- NATIVE_MACHINE_GNU_ARCH, NATIVE_LOWER_ARCH, NATIVE_MACHINE_ARCH,
NATIVE_MACHINE_PLATFORM and NATIVE_MACHINE_GNU_PLATFORM work
like the counterpars without NATIVE_ prefix. Expansion of
NATIVE_LOWER_ARCH and NATIVE_MACHINE_ARCH is enforced early,
so that MACHINE_ARCH can be overriden in mk.conf to specify the
target architecture.
- Provide a default of NO for USE_CROSS_COMPILE. This will be the
main switch to activate cross-compiling and adding it now makes
it possible to merge more of the patches for specific packages.
- Set --build and --host when cross-compiling, the former using the
just added variable NATIVE_MACHINE_GNU_PLATFORM.
Supported-by: Google SoC 2007
Looks good: jlam@