Add support for Intel C++

[sinetek]

Hi, here is a patch for adding support for Intel C++ compiler.
There's two intel compilers, but the old one is going to be deprecated, so I only bothered to test with 'icx'.

diff --git a/build/cmake/init.cmake b/build/cmake/init.cmake
index ed0cb89f7c..7ee134644b 100644
--- a/build/cmake/init.cmake
+++ b/build/cmake/init.cmake
@@ -178,6 +178,8 @@ if(WIN32)
         set(wxCOMPILER_PREFIX "gcc")
     elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
         set(wxCOMPILER_PREFIX "clang")
+    elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "IntelLLVM")
+        set(wxCOMPILER_PREFIX "icx")
     else()
         message(FATAL_ERROR "Unknown WIN32 compiler type")
     endif()

[sinetek]

I think the value should be vc instead of icx to make cmake happy.

[vadz]

We used to support icc in the past but I have no idea if it's still supported, i.e. if the code actually compiles/works correctly with it. Any serious effort to revive support for it should include adding a CI build testing it, otherwise it will just inevitably bit rot away again.

If you can do this, please open a PR adding a CI job using icc and the necessary changes to make it work. TIA!

[imciner2]

icc is different from icx. icx is the newer LLVM-based Intel compiler and icc is their older one that is now deprecated (to be removed in a year or two actually).

When I tried compiling wx with icx in August of last year it worked.

[vadz]

Sorry, I didn't realize the name has changed. But the gist remains the same: for a compiler to be really supported, it needs to be tested in the CI. It looks like Intel even has an apt repository, so adding a job using it should be pretty simple, if anybody is interested in doing it.

[sinetek]

Yes, I don't know what a CI is. So someone feel free to take this issue. I wanted to leave documentation for those googling the error messages.

[vadz]

CI is "continuous integration" and refers to the builds done automatically on every push and, even more importantly, every PR done in this repository. It ensures that new changes at least don't break the build and it's even more crucial to have it for rarely used compilers like this one.

It's not difficult to add a new CI job, see .github/workflows/ci.yml, but someone needs to do it.