Fewer shared specs for library #2441

Job	Run time
RuboCop	50s
specs (windows, 3.4.9)	3m 19s
specs (macos, 3.3.11)	1m 35s
specs (ubuntu, 4.0.4, --enable-frozen-string-literal)	1m 34s
specs (ubuntu, 4.0.4, LC_ALL=C)	1m 35s
specs (macos, 3.4.9)	1m 20s
specs (ubuntu, 4.0.4, --repeat 2)	2m 30s
specs (ubuntu, 3.4.9)	1m 45s
specs (ubuntu, 4.0.4)	1m 35s
specs (ubuntu, 4.0.4, --parser=parse.y)	1m 40s
specs (windows, 4.0.4)	3m 45s
specs (ubuntu, 3.3.11)	1m 37s
specs (windows, 3.3.11)	3m 36s
specs (macos, 4.0.4)	1m 38s
	28m 19s

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