Optimize cemented callbacks #1974

Job	Run time
macOS [UBSAN] [lmdb \| clang]	32m 39s
Linux [UBSAN] [lmdb \| clang]	41m 12s
macOS [ASAN] [lmdb \| clang]	35m 30s
Linux [ASAN] [lmdb \| clang]	37m 51s
macOS [TSAN] [lmdb \| clang]	31m 16s
Linux [ASAN_INT] [lmdb \| clang] (Errors Ignored)	39m 59s
macOS [UBSAN] [rocksdb \| clang]	43m 25s
Linux [TSAN] [lmdb \| clang]	38m 56s
macOS [ASAN] [rocksdb \| clang]	1h 12m 37s
Linux [LEAK] [lmdb \| clang] (Errors Ignored)	37m 55s
macOS [TSAN] [rocksdb \| clang]	47m 34s
Linux [UBSAN] [rocksdb \| clang]	44m 33s
Linux [ASAN] [rocksdb \| clang]	47m 51s
Linux [ASAN_INT] [rocksdb \| clang] (Errors Ignored)	49m 48s
Linux [LEAK] [rocksdb \| clang] (Errors Ignored)	52m 10s
	10h 53m 16s

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