android: Add getpwent/setpwent/endpwent

[sylfn]

Closes #3014
Supersedes #3015

Description

This pull request adds support for getpwent, setpwent and endpwent for Android targets. I have no idea how to gate them behind API >= 26, and previous PR didn't do this either so I assume it's fine

Sources

https://cs.android.com/android/platform/superproject/main/+/main:bionic/libc/include/pwd.h;l=89;drc=02ce401d1e2b31586c94c8b6999364bbbce27388

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

Tried testing locally on x86_64-unknown-linux-gnu (NixOS) host with:

• cross (git), cross test --target aarch64-linux-android (NDK r25b, API 28, Android 9.0.0_r1, from their a bit dated Dockerfile): failed to compile, errors on IFF_NO_CARRIER, TUN_F_*, PR_* and several others.
• cargo zigbuild --tests --target aarch64-linux-android (zig 0.16.0): failed due to missing include sys/param.h

@rustbot label +stable-nominated

[rustbot]

Some changes occurred in an Android module

cc @maurer

[JohnTitor]

You need to skip the test on

libc/libc-test/build.rs

Line 1815 in f4d6777

fn test_android(target: &str) {

to make CI pass.
@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[sylfn]

@rustbot ready