Add RubyFeatures#supports_syntax_suggest? #572

Job	Run time
Rubocop	37s
Rubocop	37s
Ruby 2.7 (Windows)	2m 46s
Ruby 2.7 (Windows)	2m 46s
Ruby 2.6 (Windows)	3m 49s
Ruby 2.6 (Windows)	3m 49s
Ruby 2.5 (Windows)	3m 8s
Ruby 2.5 (Windows)	3m 8s
Ruby 2.4 (Windows)	1m 53s
Ruby 2.4 (Windows)	1m 53s
Ruby 2.3 (Windows)	4m 33s
Ruby 2.3 (Windows)	4m 33s
Ruby 2.2 (Windows)	1m 59s
Ruby 2.2 (Windows)	1m 59s
Ruby 2.1.9 (Windows)	1m 14s
Ruby 2.1.9 (Windows)	55s
Legacy Ruby Builds (2.0)	52s
Legacy Ruby Builds (2.0)	52s
Legacy Ruby Builds (1.9.3)	38s
Legacy Ruby Builds (1.9.3)	38s
Legacy Ruby Builds (1.9.2)	38s
Legacy Ruby Builds (1.9.2)	38s
Legacy Ruby Builds (1.8.7)	47s
Legacy Ruby Builds (1.8.7)	47s
Legacy Ruby Builds (REE)	37s
Legacy Ruby Builds (REE)	37s
Legacy Ruby Builds (JRuby 1.7)	52s
Legacy Ruby Builds (JRuby 1.7)	52s
Legacy Ruby Builds (JRuby 1.7 1.8 mode)	45s
Legacy Ruby Builds (JRuby 1.7 1.8 mode)	45s
Legacy Ruby Builds (JRuby 9.1.17.0)	57s
Legacy Ruby Builds (JRuby 9.1.17.0)	57s
Ruby 3.2	1m 50s
Ruby 3.2	1m 50s
Ruby 3.1	1m 46s
Ruby 3.1	1m 46s
Ruby 3.0	2m 34s
Ruby 3.0	2m 34s
Ruby 2.7	3m 2s
Ruby 2.7	3m 2s
Ruby 2.6	4m 9s
Ruby 2.6	4m 9s
Ruby 2.5	3m 40s
Ruby 2.5	3m 40s
Ruby 2.4	1m 49s
Ruby 2.4	1m 49s
Ruby 2.3	1m 52s
Ruby 2.3	1m 52s
Ruby 2.2	2m 32s
Ruby 2.2	2m 32s
Ruby 2.1.9	11s
Ruby 2.1.9	12s
Ruby ruby-head	28s
Ruby ruby-head	28s
Ruby jruby-9.2.13.0	2m 11s
Ruby jruby-9.2.13.0	2m 11s
Ruby 2.7 with diff-lcs 1.3	2m 57s
Ruby 2.7 with diff-lcs 1.3	2m 57s
Ruby 2.7 with diff-lcs 1.4.3	3m 13s
Ruby 2.7 with diff-lcs 1.4.3	3m 13s
	1h 56m 20s

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