Following up, issue resolved with a (related?) flag: `--with-cc-opt`. I removed the `-m64` directive, and configure succeeded on arm64 / aarch64 CPU.

Configure failed with:

--with-cc-opt="-m64 -march=native -mtune=native -DTCP_FASTOPEN=23 -g -O3 -fstack-protector-strong -flto -ffat-lto-objects -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wimplicit-fallthrough=0 -Wno-deprecated-declarations -fcode-hoisting -Wp,-D_FORTIFY_SOURCE=2" \

Configure succeeded with:

--with-cc-opt="-m64 -march=native -mtune=native -DTCP_FASTOPEN=23 -g -O3 -fstack-protector-strong -flto -ffat-lto-objects -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wimplicit-fallthrough=0 -Wno-deprecated-declarations -fcode-hoisting -Wp,-D_FORTIFY_SOURCE=2" \

It's not clear to me if the above change is related to a suitable AIO, but the issue is resolved.