Whether an external or internal getauxval implementation is used.
const extern_getauxval = switch (builtin.zig_backend)
const extern_getauxval = switch (builtin.zig_backend) {
// Calling extern functions is not yet supported with these backends
.stage2_arm,
.stage2_powerpc,
.stage2_riscv64,
.stage2_sparc64,
=> false,
else => !builtin.link_libc,
}