config/scripts/switch-arch: fix build on aarch64 and riscv64 hosts

Ensure that the host compiler builds with -DNATIVE_BITWIDTH_SMALLER_THAN_HOST_BITWIDTH
on aarch64 and riscv64 hosts for 32-bit target architectures, otherwise host pointers
can end up being truncated to 32-bits causing a segfault running forthstrap.

Resolves: https://github.com/openbios/openbios/issues/18
Resolves: https://github.com/openbios/openbios/issues/25
Closes: https://github.com/openbios/openbios/pull/12
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

config/scripts/switch-arch

diff --git a/config/scripts/switch-arch b/config/scripts/switch-arch
index 013116b..2c20d27 100755
--- a/config/scripts/switch-arch
+++ b/config/scripts/switch-arch
@@ -38,7 +38,8 @@
     if test "$cpu" = "sparc64" -o "$cpu" = "ia64" \
         -o "$cpu" = "amd64" -o "$cpu" = "x86_64" \
         -o "$cpu" = "powerpc64" -o "$cpu" = "ppc64" \
-        -o "$cpu" = "ppc64le" -o "$cpu" = "alpha" ; then
+        -o "$cpu" = "ppc64le" -o "$cpu" = "alpha" \
+        -o "$cpu" = "aarch64" -o "$cpu" = "riscv64" ; then
         echo 64
     else
         echo 32