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.
Small changes to the text and CMake code for the fourth step of the
tutorial:
* Remove parameter from endfunction call
* Standardize on "binary directory" for test location
* Add additional information about a Release build.
Issue: #22663
* Fix typo in #include
* Remove CMakeLists file that users should create
* Clarify which files users are expected to create
* Highlight the importance of configuring TutorialConfig.h.in after
the MY_MATH option has been set
* Update minimum required version to 3.10
* Use VERSION argument to project command rather than separate variables
* Replace `endif(USE_MYMATH)` with more modern `endif()`
* Simplify the call to 'configure_file()'
* Add comments to tutorial.cxx to use as anchors in documentation
* Remove CMakeLists and TutorialConfig.h.in files that users should
create. Consequently, remove Step1 from CMake tests.
Revert the changes from commit a2a90f41e3 (Tests: require C++14 for the
Tutorial, 2019-03-21, v3.15.0-rc1~41^2~2) for the content in its new
home. In commit d50b31be35 (Clang: For MSVC ABI do not use modes older
than C++14, 2019-07-23) we fixed the C++ standard selection for GNU-like
Clang with the MSVC ABI so the test code itself no longer needs to do
it. In particular, changing the tests in this way broke the tutorial's
narrative.
Migrate tutorial text from individual `directions.txt` files to the main
tutorial document. Add some comments to source code to provide anchors
for inclusion.
