Add new benchmark for getivar with T_CLASS and T_MODULE (#449) #1541

Job	Run time
test (ruby)	56s
test (truffleruby)	1m 16s
benchmark-default (head)	11m 17s
test (head)	51s
benchmark-ractor (ruby)	13m 54s
benchmark-ractor (head)	12m 19s
benchmark-default (truffleruby)	15m 32s
benchmark-default (ruby)	11m 17s
benchmark-ractor-only (ruby)	55s
benchmark-ractor-only (head)	44s
benchmark-graph	55s
benchmark-run-once	1m 24s
all-tests	2s
	1h 11m 22s

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