Replace handwritten Debug impls with derives

[tgross35]

s_no_extra_traits! doesn't derive Debug so there are a lot of handwritten implementations. However, since we have a derive-like solution for unions now (printing them like an opaque struct), there really isn't any reason these can't all be derived.

Add derive(Debug) to s_no_extra_traits, still gated behind feature = "extra_traits", which allows getting rid of manual implementations.

[rustbot]

Some changes occurred in OpenBSD module

cc @semarie

Some changes occurred in solarish module

cc @jclulow, @pfmooney

Some changes occurred in the Android module

cc @maurer

[tgross35]

Verified that the following work:

rustc --print target-list | lines | find -v -r '^(aarch64-unknown-teeos|amdgcn-amd-amdhsa|avr-none|hexagon-unknown-none-elf|i686-unknown-hurd-gnu|i686-pc-nto-qnx700|m68k-unknown-.*|riscv64gc-unknown-netbsd|x86_64-lynx-lynxos178|x86_64-unknown-hurd-gnu|x86_64-unknown-linux-none|xtensa-esp32.*)$' | each { |$tgt| print $tgt; cargo c -p libc --target $tgt -Zbuild-std=core; cargo c -p libc --target $tgt --features extra_traits -Zbuild-std=core }
rustc --print target-list | lines | find freebsd | each { |tgt| for version in [11, 12, 13, 14, 15] { print $"($tgt) freebsd($version)"; RUST_LIBC_UNSTABLE_FREEBSD_VERSION=$version cargo c -p libc --target $tgt -Zbuild-std=core; RUST_LIBC_UNSTABLE_FREEBSD_VERSION=$version cargo c -p libc --target $tgt --features extra_traits -Zbuild-std=core } }

All of the skipped targets are failed on main (I'm a bit surprised about hurd)