spirv: saturating arithmetic implementation

[ivanstepanovftw]

This PR implements saturating arithmetic, like +|, -|=, etc for SPIR-V. It emulates the behavior like GCC STL does, without using special opcodes from the extended set (like OpenCL.std). I need this for Tsetlin machine implementation.

[ivanstepanovftw]

cc @alichraghi

[alichraghi]

the tests on test/behavior/saturating_arithmetic.zig are fails. you can locally run the test using zig-spirv-test-executor:

zig test test/behavior/saturating_arithmetic.zig \
    --test-runner /path/to/zig-spirv-test-executor/src/test_runner.zig \
    -target spirv64-vulkan \
    -mcpu vulkan_v1_2+int64+float16+float64 \
    -fno-llvm \
    --test-cmd /path/to/zig-spirv-test-executor/zig-out/bin/zig-spirv-test-executor \
    --test-cmd --platform \
    --test-cmd radv \
    --test-cmd-bin -femit-bin=build/spv.spv

Also, i genuinely ask you to avoid using AI to fix the spirv backend. Though, you're welcome to ask me questions about SPIR-V at any time!

[ivanstepanovftw]

Nice. I didn't know about this test, I have only tested locally with simple kernel. Personally I like builder functions more than duplicating one for *Overflow, one for *Sat.

I will try to run tests now.

I will also add missing tests, so #24315 never regress.

[ivanstepanovftw]

Seems like riscv64 does not know how to subtract zero from signed integers.