Vector: sparse ewiseadd bug (cpu)

[vkutuev]

Test vector.eadd_sub_pow2 works fine with OpenCL accelerators. Tested with

• Intel(R) OpenCL Graphics device: Intel(R) Iris(R) Xe Graphics
• Portable Computing Language device: cpu-znver4-13th Gen Intel(R) Core(TM) i5-1340P (POCL)

[ RUN      ] vector.eadd_sub_pow2
[       OK ] vector.eadd_sub_pow2

But this test fails on CPU.

[ RUN      ] vector.eadd_sub_pow2
Value of: std::abs(expected - actual) <= error
  Actual: false
...
Value of: std::abs(expected - actual) <= error
  Actual: false
[  FAILED  ] vector.eadd_sub_pow2

To Reproduce

Run vector tests without OpenCL accelerators:

1. Replace SPLA_GTEST_MAIN_WITH_FINALIZE_PLATFORM(0) in tests/test_vector.cpp:500
   with SPLA_GTEST_MAIN_WITH_FINALIZE_NO_ACC()
2. Rebuild project
3. Run tests