CMake

faster merge code #1113

Job	Run time
full-build (ubuntu-latest, "-DL0_SAMPLING")	20s
full-build (ubuntu-latest, "-DNO_EAGER_DSU")	19s
full-build (ubuntu-latest, "")	22s
full-build (ubuntu-20.04, "-DL0_SAMPLING")	35s
full-build (ubuntu-20.04, "-DNO_EAGER_DSU")	34s
full-build (ubuntu-20.04, "")	35s
	2m 45s

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