Update to DMD v2.081.2

[ibuclaw]

@belka-ew - These are the fixes to merge into the other release branches.

After this, I'm syncing master with dmd/master as per #704.

[belka-ew]

👍

@jpf91 requested to update DRUNTIME_SOVERSION and PHOBOS_SOVERSION in libphobos/configure.ac and libphobos/configure, otherwise shared libraries are named libgphobos.so.76.0.2 and libgdruntime.so.76.0.2.

[ibuclaw]

Ah, right, done.

[belka-ew]

Still strange: libgphobos.so.81.0.2 and libgdruntime.so.81.0.2. DMD's Phobos is versioned as libphobos2.so.0.81.2. But it least it is clear what version it is.

[jpf91]

Thanks to both of you.

@belka-ew libgphobos.so.81.0.2 follows the libtool scheme: https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html and the SONAME is libgphobos.so.81.

In the DMD case, the SONAME is libphobos.so.0.81 instead, so essentially we name the library libphobos.so and DMD names the library libphobos.so.0. The rest of the versioning is then similar, both use 81 as major/ABI version. I don't know if there is any special meaning to using the second vs third version component, we set 2 as the third component, dmd as the second. I guess the difference is in the Programs using the previous version may use the new version as drop-in replacement, but programs using the new version may use APIs not present in the previous one case? But I don't know how this actually works in detail...

[ibuclaw]

I guess the difference is in the Programs using the previous version may use the new version as drop-in replacement, but programs using the new version may use APIs not present in the previous one case? But I don't know how this actually works in detail...

Sounds like you'll be relying on the assumption that no ABI breaking changes have occurred between versions.