Add gnu_get_[version|release] for glibc

[LegNeato]

See https://sourceware.org/git/?p=glibc.git;a=blob;f=csu/version.c;h=8c0ed79c01223e1f12b54d19f90b5e5b7dd78d27;hb=HEAD#l51 and http://refspecs.linux-foundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/libc-gnu-get-libc-version-1.html

[rust-highfive]

r? @Amanieu

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[Amanieu]

@bors r+

[bors]

📌 Commit f415078 has been approved by Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit f415078 with merge f1d38be...

[bors]

💔 Test failed - checks-actions

[LegNeato]

I don't think this failure was caused by my code, any action on me?

[LegNeato]

When I had the include path wrong it failed in CI. Once I had the correct include path it succeeded. So something in CI was able to pick it up.

The functions were introduced in version 2.1, which was released in 1999:

https://sourceware.org/git/?p=glibc.git;a=blob;f=csu/Versions;h=8e1b21948e8d7568c3e61caeaeb719cdaf110272;hb=HEAD#l6

I don't see anything to suggest it is optional / can be turned off, though the GNU manual notes:

This function is missing on some platforms: macOS 11.1, FreeBSD 13.0, NetBSD 9.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

It looks like alpine linux uses uclibc, which does not include the header. Does homu use alpine linux as its docker image base? If so that could account for the discrepancy...CI uses an image with glibc so the header was found and passed, homu uses alpine so it can't find the header and the merge fails?

[Amanieu]

@bors r+

[bors]

📌 Commit f49efe4 has been approved by Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit f49efe4 with merge aa0f5b5...

[bors]

💔 Test failed - checks-actions

[Amanieu]

@bors retry

[bors]

⌛ Testing commit f49efe4 with merge f742325...

[bors]

☀️ Test successful - checks-actions, checks-cirrus-freebsd-12, checks-cirrus-freebsd-13, checks-cirrus-freebsd-14
Approved by: Amanieu
Pushing f742325 to master...