[SYCL] Fix sycl::atomic regression

[AlexeySachkov]

This is a follow-up for #18839 which broke host compilation of sycl::atomic.

The actual fix is just an addition of #include <sycl/__spirv/spirv_ops.hpp> to sycl/atomic.hpp.

However, I didn't want spirv_ops.hpp to appear again in sycl/detail/core.hpp and therefore I went further to make sure that sycl/atomic.hpp isn't used by sycl/accessor.hpp which prompted other changes in this PR.

[AlexeySachkov]

Wow, that Windows issue is persistent

I honestly struggle to understand how this patch could cause it at all:

# .---command stderr------------
# | In file included from D:\github\_work\llvm\llvm\llvm\sycl\test-e2e\DeviceLib\exp\exp-std-complex-float-edge-cases.cpp:10:
# | D:\github\_work\llvm\llvm\llvm\sycl\test-e2e\DeviceLib\exp\exp-std-complex-edge-cases.hpp:24:29: error: constexpr variable 'testcases' must be initialized by a constant expression
# |    24 |   constexpr std::complex<T> testcases[] = {
# |       |                             ^             ~
# |    25 |       /* 0 */ std::complex<T>(1.e-6, 1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    26 |       /* 1 */ std::complex<T>(-1.e-6, 1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    27 |       /* 2 */ std::complex<T>(-1.e-6, -1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    28 |       /* 3 */ std::complex<T>(1.e-6, -1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    29 | 
# |    30 |       /* 4 */ std::complex<T>(1.e+6, 1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    31 |       /* 5 */ std::complex<T>(-1.e+6, 1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    32 |       /* 6 */ std::complex<T>(-1.e+6, -1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    33 |       /* 7 */ std::complex<T>(1.e+6, -1.e-6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    34 | 
# |    35 |       /* 8 */ std::complex<T>(1.e-6, 1.e+6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    36 |       /* 9 */ std::complex<T>(-1.e-6, 1.e+6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    37 |       /* 10 */ std::complex<T>(-1.e-6, -1.e+6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    38 |       /* 11 */ std::complex<T>(1.e-6, -1.e+6),
# |       |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |    39 | 
# | D:\github\_work\llvm\llvm\llvm\sycl\test-e2e\DeviceLib\exp\exp-std-complex-float-edge-cases.cpp:12:21: note: in instantiation of function template specialization 'test<float>' requested here
# |    12 | int main() { return test<float>(); }
# |       |                     ^
# | D:\github\_work\llvm\llvm\llvm\sycl\test-e2e\DeviceLib\exp\exp-std-complex-edge-cases.hpp:63:32: note: floating point arithmetic produces a NaN
# |    63 |       /* 32 */ std::complex<T>(NAN, NAN),
# |       |                                ^
# | C:\Program Files (x86)\Windows Kits\10\include\10.0.22[621](https://github.com/intel/llvm/actions/runs/15729393865/job/44326718876?pr=19015#step:27:636).0\ucrt\corecrt_math.h:94:39: note: expanded from macro 'NAN'
# |    94 | #define NAN        (-(float)(INFINITY * 0.0F))
# |       |                                       ^
# | 1 error generated.
# `-----------------------------
# error: command failed with exit status: 1

And I haven't been able to reproduce it so far, but I will make more attempts