Optimize `merge` algorithm for data sizes equal or greater then 4M items with SLM cache usage #6

Job	Run time
HOST,bknd=tbb,cmplr=icx-cl,windows-latest,std=c++17,cfg=release	14m 22s
clang-format	23s
CPU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	2m 33s
HOST,bknd=tbb,cmplr=cl,windows-latest,std=c++17,cfg=release	14m 42s
HOST,bknd=omp,cmplr=clang++,macos-latest,std=c++17,cfg=release	4m 19s
FPGA_EMU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	3m 25s
CPU,bknd=dpcpp,cmplr=icx,windows-latest,std=c++17,cfg=release	6m 23s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	5m 54s
HOST,bknd=omp,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	5m 42s
HOST,bknd=omp,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	5m 57s
HOST,bknd=tbb,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	8m 22s
HOST,bknd=tbb,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	6m 10s
HOST,bknd=tbb,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	11m 0s
HOST,bknd=omp,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	8m 22s
HOST,bknd=tbb,cmplr=clang++,ubuntu-latest,std=с++17,cfg=release	10m 59s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++17,cfg=release	4m 54s
HOST,bknd=serial,cmplr=g++,ubuntu-latest,std=с++17,cfg=release	4m 51s
CPU,bknd=dpcpp,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	2m 23s
HOST,bknd=tbb,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	4m 46s
HOST,bknd=omp,cmplr=icpx,ubuntu-latest,std=с++20,cfg=release	4m 0s
	2h 9m 27s

Provide feedback