Ruby

Add signature for `Fiber#blocking` #7070

Job	Run time
C99_compile (3.4)	48s
C99_compile (head)	1m 13s
test (3.1, test)	2m 52s
test (3.4, test)	3m 16s
test (3.4, rubocop validate test_doc build test_generate_stdlib raap)	2m 48s
test (3.4, stdlib_test)	2m 20s
test (head, test)	3m 47s
test (3.4, test, --enable-frozen-string-literal)	3m 20s
test (3.2, test)	2m 54s
test (head, stdlib_test rubocop)	3m 1s
test (3.4, stdlib_test, --enable-frozen-string-literal)	2m 23s
test (3.3, test)	3m 13s
test (3.4, typecheck_test)	1m 24s
	33m 19s

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