some NFC refactorings #18458

Job	Run time
race_dashboard	3m 51s
dashboard	2m 11s
aux	4m 4s
old	7m 6s
race	6m 56s
gvisor	4m 2s
build	5m 10s
arch (presubmit_arch_windows)	3m 40s
arch (presubmit_arch_darwin)	3m 45s
arch (presubmit_arch_freebsd)	6m 22s
arch (presubmit_arch_netbsd)	3m 50s
arch (presubmit_arch_executor)	3m 19s
arch (presubmit_arch_openbsd)	3m 58s
arch (presubmit_arch_linux)	10m 3s
	1h 8m 17s

Provide feedback