options/posix: implement putpwent #3780

Job	Run time
Compile sysdeps (dripos)	2m 14s
Build mlibc (x86_64, mlibc, gcc)	4m 17s
Compile sysdeps (lemon)	2m 13s
Build mlibc (x86_64, mlibc-static, gcc)	2m 40s
Compile sysdeps (aero)	2m 17s
Build mlibc (x86_64, mlibc-shared, gcc)	6m 45s
Compile sysdeps (ironclad)	2m 14s
Build mlibc (x86_64, mlibc-ansi-only, gcc)	2m 38s
Compile sysdeps (lyre)	2m 13s
Build mlibc (x86_64, mlibc-headers-only, gcc)	2m 33s
Compile sysdeps (keyronex)	2m 31s
Build mlibc (riscv64, mlibc, gcc)	4m 3s
Build mlibc (riscv64, mlibc-static, gcc)	4m 5s
Compile sysdeps (managarm)	2m 30s
Compile sysdeps (vinix)	2m 16s
Build mlibc (riscv64, mlibc-shared, gcc)	2m 38s
Build mlibc (riscv64, mlibc-ansi-only, gcc)	2m 26s
Build mlibc (riscv64, mlibc-headers-only, gcc)	1m 53s
Build mlibc (aarch64, mlibc, gcc)	4m 27s
Build mlibc (aarch64, mlibc-static, gcc)	3m 27s
Build mlibc (aarch64, mlibc-shared, gcc)	3m 12s
Build mlibc (aarch64, mlibc-ansi-only, gcc)	2m 41s
Build mlibc (aarch64, mlibc-headers-only, gcc)	2m 14s
Build mlibc (x86, mlibc, gcc)	3m 34s
Build mlibc (x86, mlibc-static, gcc)	3m 14s
Build mlibc (x86, mlibc-shared, gcc)	4m 20s
Build mlibc (x86, mlibc-ansi-only, gcc)	3m 33s
Build mlibc (x86, mlibc-headers-only, gcc)	2m 12s
Build mlibc (x86_64, mlibc, clang)	2m 33s
	1h 27m 53s

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