Support IELR(1) Parser Generation #1401

Job	Run time
check-misc (head)	11s
test-windows (head)	1m 40s
steep-check (head)	12s
test-ruby (head, master)	6m 9s
test-memory (head)	29s
test-ruby (3.0, master)	5m 59s
ruby-versions / Generate Ruby versions	4s
test-cpp (head, g++)	13s
test (2.5)	25s
test (2.6)	28s
test-cpp (head, clang++)	20s
test (2.7)	31s
test (3.0)	14s
test (3.1)	17s
test (3.2)	17s
test (3.3)	16s
test (head)	16s
	18m 1s

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