Intel: Add support for Intel LLVM-based compilers

Here is a first pass at support for the Intel LLVM-based compilers in oneAPI. It seems to work for Fortran, C, and C++ (ifx, icx, and icpx) on Linux. More testing is needed for Windows and DPC++. I did the testing before rebasing on the latest master. I see that some other changes have gone in regarding the new LLVM-based compilers for Visual Studio.

I am making the merge request while continuing to test hoping to get feedback on whether this approach looks reasonable.

The last two commits in the sequence were trying to fix some test failures due to paths with symbolic links not matching. They could probably be excluded.

Cc: @Harini
Issue: #21560, #21561 (closed)
Topic-rename: intel-llvm-compilers

added 9 commits

• 5afa1629 - Add compiler modules for IntelLLVM compilers
• f00da908 - Update IntelLLVM variables and IDs
• a7ebc93b - Added Platform modules for IntelLLVM
• c204d98e - Updated library finding modules impacted by IntelLLVM compilers
• 9c826e17 - Update Fortran tests to match IntelLLVM as well as Intel
• dc5df4dc - Added support for IntelLLVM in Tests/Module/WriteCompilerDetectionHeader
• 4bf06191 - Remove warnings in Fortran test with return type on function declarations
• f1468fe4 - Canonicalize paths when comparing them
• 5892a1db - Make GCOV test more robust to symbolic links in paths

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added 8 commits

• 0e225a62 - Update IntelLLVM variables and IDs
• e5d6f4a7 - Added Platform modules for IntelLLVM
• b6de1532 - Updated library finding modules impacted by IntelLLVM compilers
• fe797219 - Update Fortran tests to match IntelLLVM as well as Intel
• d1dd63f6 - Added support for IntelLLVM in Tests/Module/WriteCompilerDetectionHeader
• d3251a8e - Remove warnings in Fortran test with return type on function declarations
• 243bbf47 - Canonicalize paths when comparing them
• c17cf7c0 - Make GCOV test more robust to symbolic links in paths

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added comp:intel-dpcpp comp:intel-llvm workflow:wip labels

changed the description

changed milestone to %3.20.0

Is this yet another variant like IntelDPCPP and IntelClang?

See #21560 an #21561 (closed) for those two.

changed title from WIP: Support for Intel LLVM-based compilers to WIP: Intel: Add support for Intel LLVM-based compilers

changed the description

@ax3l You will be interested in this I expect.

Edit: @scivision as well

Lets drop the components that are related to adding DPC++ as a language such as:

• Modules/Compiler/IntelLLVM-DPCPP-DetermineCompiler.cmake
• Modules/Compiler/IntelLLVM-DPCPP.cmake

Adding a DPC++ as a new language to CMake should be done ( if at all ) as a separate merge request after we have figured out the best way to support the new LLVM based compilers.

In a couple places you have updated if( <> MATCHES "Intel") to handle "IntelLLVM". I don't think this change is needed as the original MATCHES should capture both

added 4 commits

• af79930f - Remove incomplete support for DPCPP as a language
• a8972c43 - Remove changes that associate ISPC with IntelLLVM
• 3990bd9e - Avoid macro name clash between Intel and IntelLLVM compilers
• 1983bc57 - When regex matching, only explicitly match "LLVM" when required

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added 1 commit

• 1356066c - Fix C/C++ version number computation for IntelLLVM compilers

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added 4 commits

• ff22e4fb - Update IDs for Intel LLVM-based compilers
• bca5d42b - Remove warnings in Fortran test with return type on function declarations
• 0c8f293b - Canonicalize paths when comparing them
• d8f1010f - Make GCOV test more robust to symbolic links in paths

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removed comp:intel-dpcpp label