[SYCL][NFC] Update includes in DPC++ headers. (#10648)
These changes were done in semi-automatic mode by [include what you
use](https://github.com/include-what-you-use/include-what-you-use/)
tool. The
caveat is that this tool doesn't support SYCL compilation mode, so it
analyses
only host code and I had to manually adjust includes for the device
compilation.
The tool annotated each include with the symbols declared in the
included header
and used in the code.
I tired to apply following structure to includes where it's possible:
```c++
// <copyright header>
#pragma once
#include "local/includes"
#include <sycl/includes>
#ifdef ..
#include <conditional/includes>
#endif
#include <standard_library>
```
Removed sycl/include/sycl/detail/sycl_fe_intrins.hpp and
sycl/include/sycl/detail/service_kernel_names.hpp - declarations from
these headers
are used only once, so there is sense in moving them to a separate
headers.
I've put a few comments for follow-up actions:
1. sycl/include/sycl/handler.hpp includes 57 headers, which seems to
much.
2. sycl/include/sycl/info/info_desc.hpp and
sycl/include/sycl/detail/info_desc_helpers.hpp - includes .def files,
which
depend on previous includes, doesn't sound like a good idea.
3. sycl/include/sycl/detail/kernel_desc.hpp - uses __SYCL_EXPORT, which
doesn't
sounds right to me, but I might be missing something.
