Eliminate code duplication when increasing workgroup size

[KseniiaBakina]

[akukanov]

A good practice is to describe the purpose of a patch - what problem(s) it intends to solve, etc. This patch has no description at all.

Also I am always suspicious of "refactoring" patches that increase the line count. LOC is the simplest yet often relevant metric of code complexity. This patch makes one file 19 lines shorter and another file 66 lines longer; that does not at all seem a useful refactoring.

[KseniiaBakina]

A good practice is to describe the purpose of a patch - what problem(s) it intends to solve, etc. This patch has no description at all.

Also I am always suspicious of "refactoring" patches that increase the line count. LOC is the simplest yet often relevant metric of code complexity. This patch makes one file 19 lines shorter and another file 66 lines longer; that does not at all seem a useful refactoring.

The pool request is not ready yet. The purpose of the pull request is to minify the code in the parallel_backend_sycl.h file functions. It will be convenient to look at the functions and understand what the code does after the code reduction.

[dmitriy-sobolev]

Closing this PR due to its controversial impact on the code readability.