Support Apple Silicon and aarch64 Linux

This PR adds support for aarch64 hosts, most commonly Apple Silicon Macs. Updating the version of config.guess from the ancient copy bundled with the deps makes everything work. Surprisingly, it seems like all of the GNU tools built for aarch64 even back in 2006, despite the architecture not having… existed.

os161-container/Dockerfile

@@ -10,12 +10,16 @@ RUN mkdir -p /os161/tools/bin; \
     mkdir -p /os161/tools/share/man/man1; \
     mkdir -p /os161/tools/share/mk;
 
+# Install a newer version of config.guess with ARM support. Pin it to a specific commit for stability.
+ADD https://git.savannah.gnu.org/cgit/config.git/plain/config.guess?id=20403c5701973a4cbd7e0b4bbeb627fcd424a0f1 /tmp/config.guess
+RUN chmod +x /tmp/config.guess
 
 COPY dependencies/os161-binutils.tar.gz /binutils.tar.gz
 RUN mkdir /binutils-src; \
     tar -xf /binutils.tar.gz -C /binutils-src --strip-components 1
 WORKDIR /binutils-src
 
+RUN cp -f /tmp/config.guess .
 RUN find . -name '*.info' | xargs touch; \
     ./configure --nfp --disable-werror --target=mips-harvard-os161 --prefix=/os161/tools; \
     make -j 4 && make install; \
@@ -30,6 +34,7 @@ RUN mkdir /gcc-src; \
     tar -xf /gcc.tar.gz -C /gcc-src --strip-components 1
 WORKDIR /gcc-src
 
+RUN cp -f /tmp/config.guess .
 RUN CFLAGS="-std=gnu89" ./configure -nfp --disable-shared --disable-threads \
 	--disable-libmudflap --disable-libssp --target=mips-harvard-os161 --prefix=/os161/tools; \
     make -j 4 && make install; \
@@ -65,12 +70,14 @@ COPY dependencies/os161-gdb.tar.gz /os161-gdb.tar.gz
 RUN mkdir /os161-gdb/ && tar -xf /os161-gdb.tar.gz -C /os161-gdb --strip-components 1
 
 WORKDIR /os161-gdb
+RUN cp -f /tmp/config.guess .
 RUN CFLAGS="-std=gnu89" ./configure --target=mips-harvard-os161 --prefix=/os161/tools --disable-werror && \
     make && make install
 
 WORKDIR /
 RUN rm -rf /os161-gdb /os161-gdb.tar.gz
 
+RUN rm -f /tmp/config.guess
 RUN cd /os161/tools/bin && sh -c 'for i in mips-*; do ln -s /os161/tools/bin/$i /os161/tools/bin/cs350-`echo $i | cut -d- -f4-`; done'
 
 RUN python3 -m pip install -U prettytable