more eagerly check for cyclicity of variables in cycle detecting stac… #16

Job	Run time
build-test (windows-latest, stable, x86_64-pc-windows-msvc)	16m 6s
build-test (macos-11, stable, x86_64-apple-darwin)	8m 40s
build-test (ubuntu-22.04, stable, x86_64-unknown-linux-gnu)	5m 28s
build-test (ubuntu-20.04, stable, x86_64-unknown-linux-gnu, true)	6m 36s
build-test (ubuntu-20.04, stable, i686-unknown-linux-gnu)	8m 33s
build-test (ubuntu-20.04, 1.70, x86_64-unknown-linux-gnu)	3m 31s
build-test (ubuntu-20.04, beta, x86_64-unknown-linux-gnu)	4m 29s
build-test (ubuntu-20.04, nightly, x86_64-unknown-linux-gnu)	6m 15s
logtalk-test	0s
release	0s
	59m 38s

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