With the Zig 0.9.0 release (2021-12-20), the configlet binary now has
30 KiB of bloat in the comment section, repeating the clang version many
times.

Before this commit:

    $ readelf -p .comment ./configlet

    String dump of section '.comment':
      [     0]  clang version 13.0.1 (git@github.com:ziglang/zig-bootstrap.git 74211dd7f7e7174a2027641dfcfdb3fc5df62f0c)
      [...] (repeat for 30 KB)
      [  7969]  clang version 13.0.1 (git@github.com:ziglang/zig-bootstrap.git 74211dd7f7e7174a2027641dfcfdb3fc5df62f0c)
      [  79d2]  Linker: LLD 13.0.1 (git@github.com:ziglang/zig-bootstrap.git 74211dd7f7e7174a2027641dfcfdb3fc5df62f0c)

Binary size profile before this commit:

       FILE SIZE        VM SIZE
    --------------  --------------
     75.2%   368Ki  64.5%   368Ki    .text
      0.0%       0  19.6%   111Ki    .bss
     18.2%  89.1Ki  15.6%  89.1Ki    .rodata
      6.2%  30.6Ki   0.0%       0    .comment
      0.2%     816   0.1%     824    .data
      0.1%     640   0.0%       0    [ELF Section Headers]
      0.1%     392   0.1%     392    [ELF Program Headers]
      0.0%      64   0.0%      64    [ELF Header]
      0.0%      63   0.0%       0    .shstrtab
      0.0%       8   0.0%       8    .got
      0.0%       8   0.0%       8    [LOAD #1 [R]]
      0.0%       4   0.0%       3    .fini
      0.0%       3   0.0%       3    .init
    100.0%   489Ki 100.0%   570Ki    TOTAL

Strip the comment section. But print it first.

With Zig 0.10.0 (2022-10-31), `zig cc` now properly uses the `--passL:
-s` option that we use in `config.nims`. So we can remove the `-s` flag
from our post-build hook.

From the Zig 0.10.0 release notes [1]:

    `zig cc` is Zig's drop-in C compiler tool. Enhancements in this release:

    [...]
    - Integration with more linker args:

      - `--whole-archive`, `-whole-archive`
      - `--no-whole-archive`, `-no-whole-archive`
      - `-s`, `--strip-all`
      - `-S`, `--strip-debug`
    [...]

[1] https://ziglang.org/download/0.10.0/release-notes.html#zig-cc

And install Zig via script, rather than snap. One benefit is that it
allows us to pin a Zig version.

The script is adapted from one I added to the Exercism Zig repo [1].

[1] exercism/zig@9dfb95f031b1

`strip` can't strip a non-native executable.

--os:macos produced the error:

    /home/runner/work/configlet/configlet/nimdir/lib/system/dyncalls.nim(198, 10) Error: no implementation for dyncalls

Try to resolve error:

    error: LTO is not yet supported with the Mach-O object format. More details: ziglang/zig#8680
    Error: execution of an external compiler program
    'zigcc -c -w -ferror-limit=3 -pthread -target aarch64-macos-none -flto -Os
    -I/home/runner/work/configlet/configlet/nimdir/lib
    -I/home/runner/work/configlet/configlet/src
    -o /home/runner/.cache/nim/configlet_r/@m..@snimdir@slib@ssystem@sctypes.nim.c.o
    /home/runner/.cache/nim/configlet_r/@m..@snimdir@slib@ssystem@sctypes.nim.c'
    failed with exit code: 1

Disable until we can resolve the error

    CC: ../nimdir/lib/std/sysrand.nim
    /home/runner/.cache/nim/configlet_r/@m..@snimdir@slib@sstd@ssysrand.nim.c:9:10:
    fatal error: 'Security/SecRandom.h' file not found

which is due to a recent commit [1].

[1] 53a75a2 ("nimble, uuid: generate UUIDs via std/sysrand, not pragmagic/uuids", 2023-08-07)

This probably won't work immmediately.

Our `strip` doesn't support elf64-aarch64 as a target, and `zig objcopy`
doesn't have a `-R, --remove-section` option. Use llvm-strip when it's
installed.

Format with

  shfmt -i 2 -sr -kp -ci -w ./cross-compile