JSON.dump: handle unenclosed hashes regression #206

Job	Run time
ruby-versions / Generate Ruby versions	3s
ubuntu-20.04 2.3	51s
ubuntu-20.04 2.4	51s
ubuntu-20.04 2.5	56s
ubuntu-20.04 2.6	59s
ubuntu-20.04 2.7	57s
ubuntu-20.04 3.0	24s
ubuntu-20.04 3.1	25s
ubuntu-20.04 3.2	16s
ubuntu-20.04 head	18s
ubuntu-20.04 jruby	1m 10s
ubuntu-20.04 jruby-head	1m 12s
ubuntu-22.04 2.3	59s
ubuntu-22.04 2.4	52s
ubuntu-22.04 2.5	54s
ubuntu-22.04 2.6	58s
ubuntu-22.04 2.7	56s
ubuntu-22.04 3.0	19s
ubuntu-22.04 3.1	25s
ubuntu-22.04 3.2	31s
ubuntu-22.04 head	23s
ubuntu-22.04 jruby	1m 6s
ubuntu-22.04 jruby-head	1m 7s
macos-11 2.3	2m 6s
macos-11 2.4	2m 1s
macos-11 2.5	2m 5s
macos-11 2.6	2m 9s
macos-11 2.7	5m 31s
macos-11 3.0	2m 17s
macos-11 3.1	37s
macos-11 3.2	35s
macos-11 head	37s
macos-11 jruby	1m 17s
macos-11 jruby-head	1m 19s
macos-12 2.3	2m 2s
macos-12 2.4	2m 21s
macos-12 2.5	1m 53s
macos-12 2.6	2m 33s
macos-12 2.7	2m 0s
macos-12 3.0	36s
macos-12 3.1	38s
macos-12 3.2	37s
macos-12 head	56s
macos-12 jruby	1m 32s
macos-12 jruby-head	1m 55s
windows-latest 2.3	2m 1s
windows-latest 2.4	2m 57s
windows-latest 2.5	4m 23s
windows-latest 2.6	4m 20s
windows-latest 2.7	2m 50s
windows-latest 3.0	2m 1s
windows-latest 3.1	1m 54s
windows-latest 3.2	2m 17s
windows-latest head	1m 30s
windows-latest mswin	1m 50s
ubuntu-latest jruby-9.1	1m 10s
ubuntu-latest jruby-9.2	1m 21s
ubuntu-latest jruby-9.3	1m 3s
macos-latest truffleruby	2m 21s
ubuntu-latest truffleruby	52s
	1h 27m 19s

Provide feedback