Enabled CI for Windows ARM

[asmorkalov]

No description provided.

[Prasadayus]

@asmorkalov I looked into the Windows-ARM64 failures. There are two separate issues:

1. Build break: the windows-11-arm runner has C:\mingw64 on PATH, so CMake picks up MinGW's cc.exe and flips to a GNU/MinGW build (MINGW=1) even though we're on MSVC, producing GNU-style link flags MSVC can't use. Fix: -DCMAKE_ASM_COMPILER=CMAKE_ASM_COMPILER-NOTFOUND, which keeps it a pure MSVC build. (4.x builds fine because it has no such ASM block.)

2. Test failures: a multithreading issue. At 1 thread the whole suite passes; failures only show up with multiple threads under the default Windows backend ms-concurrency (PPL), which appears to have a concurrency bug on MSVC/ARM64. -DWITH_OPENMP=ON switches the parallel backend and turns the suite green; the same code also passes on Linux (pthreads) and macOS (GCD), so it's isolated to PPL, not OpenCV.

I also tried TBB, but -DBUILD_TBB=ON can't be used on Windows ARM64: 3rdparty/tbb/CMakeLists.txt:4 guards on if (WIN32 AND NOT ARM), and on ARM64 AARCH64 is true while ARM is false, so it fatal-errors ("BUILD_TBB option supports Windows on ARM only!") on the exact platform it's meant for.

Both fixes are on my fork: Prasadayus#3

cc: @abhishek-gola

[Psychlist1972]

@MugundanMCW can you address the accuracy failures @asmorkalov pointed out for Arm64? Thanks!

Pete
Microsoft

[MugundanMCW]

Hi @Psychlist1972
All accuracy test failures are now fixed. There are few failures which are failing only on GitHub actions[windows-11-arm], but these test failures are passing on actual Windows ARM64 device.
Thanks :)

[Avasam]

Is it intended to disable x86/x64 or is that just to reduce number of builds whilst testing arm64?

[abhishek-gola]

It's just to reduce number of builds while testing