speed up merging with correct pointers operation

[ivanmorozov333]

• Performance improvement

[github-actions]

⚪ 2024-07-30 06:12:25 UTC Pre-commit check for 29af54e has started.
⚪ 2024-07-30 06:15:20 UTC Check linux-x86_64-release-asan is running...
🔴 2024-07-30 08:26:32 UTC Some tests failed, follow the links below.

Test history | Ya make output

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
9822	9248	0	80	322	172

🟢 2024-07-30 08:27:30 UTC Build successful.
🟢 2024-07-30 08:28:23 UTC ydbd size 5.2 GiB changed* by +17.9 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 75ab2b2	merge: 29af54e	diff	diff %
ydbd size	5 570 361 072 Bytes	5 570 379 424 Bytes	+17.9 KiB	+0.000%
ydbd stripped size	1 199 093 424 Bytes	1 199 097 136 Bytes	+3.6 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-07-30 06:12:57 UTC Pre-commit check for 29af54e has started.
⚪ 2024-07-30 06:15:51 UTC Check linux-x86_64-release-clang14 is running...
🟢 2024-07-30 06:27:58 UTC Build successful.

[github-actions]

⚪ 2024-07-30 06:13:02 UTC Pre-commit check for 29af54e has started.
⚪ 2024-07-30 06:16:00 UTC Check linux-x86_64-relwithdebinfo is running...
🟢 2024-07-30 08:15:58 UTC Tests successful.

Test history | Ya make output

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
38495	33210	0	0	5275	10

🟢 2024-07-30 08:19:37 UTC Build successful.
🟢 2024-07-30 08:20:18 UTC ydbd size 8.1 GiB changed* by +18.0 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: 75ab2b2	merge: 29af54e	diff	diff %
ydbd size	8 677 212 552 Bytes	8 677 231 032 Bytes	+18.0 KiB	+0.000%
ydbd stripped size	471 842 208 Bytes	471 843 488 Bytes	+1.2 KiB	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}