Compile some third-party libraries with preprocessor definitions that
activate POSIX APIs even when compiler extensions are not enabled.
We already do this in libuv, inherited from the upstream buildsystem.
This extends commit f034b0f663 (CMake compilation: do not use compiler
extensions, 2020-03-14, v3.18.0-rc1~494^2).
Issue: #20454
Divert LCC compiler as a new one, instead of treating it as GNU.
Since old times, Elbrus C/C++/Fortran Compiler (LCC) by MCST has been
passing checks for GNU compilers, so it has been identified as GNU.
Now, with intent of seriously upstreaming its support, it has been
added as a separate LCC compiler, and its version displays not a
supported GCC version, but LCC version itself (e.g. LCC 1.25.19 instead
of GNU 7.3.0).
This commit adds its support for detection, and also converts basically
every check like 'is this compiler GNU?' to 'is this compiler GNU or
LCC?'. The only places where this check is untouched, is where it
regards other platforms where LCC is unavailable (primarily non-Linux),
and where it REALLY differs from GNU compiler.
Note: this transition may break software that are already ported to
Elbrus, but hardly relies that LCC will be detected as GNU; still such
software is not known.
We had complaints that people couldn't install the CMake source
tarball on some secure systems because there were "corrupt bz2
files" in it... We do not use these sample*.bz2 files anyhow
in the CMake build, so we'll just remove them.
This allows for a built in bzip and zip capability, so external tools
will not be needed for these packagers. The cmake -E tar xf should be
able to handle all compression types now as well.
