Unable to build on aarch64

[MichaelMackus]

Getting a bunch of errors during the build:

g++: error: unrecognized command-line option ‘-m64’
g++: error: unrecognized command-line option ‘-mfpmath=sse’
g++: error: unrecognized command-line option ‘-msse2’
g++: error: unrecognized command-line option ‘-m64’

I tried replacing those options with -march=armv8-a and that got Genie to compile, but having troubles with all the other libraries - these compiler options are scattered everywhere with seemingly no easy way to override them. I think we need a better way of detecting computer architecture - usually there's things like uname -m being used for these compiler switches in other software, and that seems to work well.

I tried the android-arm64 build but that didn't work, likely because I'm not on android (failed with fatal error: 'type_traits' file not found)

[bkaradzic]

And you typed?

make -R -C .build/projects/gmake-android-arm64 config=debug