Add specs for case/when with out-of-int-range Integer literals #2384

Job	Run time
RuboCop	49s
specs (ubuntu, 3.3.11)	1m 27s
specs (macos, 3.3.11)	1m 41s
specs (windows, 3.3.11)	2m 57s
specs (ubuntu, 4.0.4, LC_ALL=C)	1m 33s
specs (windows, 3.4.9)	3m 11s
specs (macos, 3.4.9)	1m 35s
specs (ubuntu, 4.0.4)	1m 34s
specs (macos, 4.0.4)	1m 25s
specs (ubuntu, 3.4.9)	1m 43s
specs (ubuntu, 4.0.4, --enable-frozen-string-literal)	1m 33s
specs (windows, 4.0.4)	3m 38s
specs (ubuntu, 4.0.4, --parser=parse.y)	1m 39s
specs (ubuntu, 4.0.4, --repeat 2)	2m 4s
	26m 49s

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