add guards support in JavascriptParser #6016

Job	Run time
lint	1m 19s
basic	1m 22s
unit	1m 1s
validate-legacy-node	11s
integration (ubuntu-latest, 10.x, a)	8m 24s
integration (ubuntu-latest, 10.x, b)	9m 1s
integration (ubuntu-latest, 20.x, a)	7m 4s
integration (ubuntu-latest, 20.x, b)	8m 6s
integration (windows-latest, 10.x, a)	11m 0s
integration (windows-latest, 10.x, b)	11m 7s
integration (windows-latest, 20.x, a)	9m 51s
integration (windows-latest, 20.x, b)	10m 18s
integration (macos-latest, 10.x, a)	10m 58s
integration (macos-latest, 10.x, b)	24m 19s
integration (macos-latest, 20.x, a)	21m 41s
integration (macos-latest, 20.x, b)	13m 25s
integration (ubuntu-latest, lts/*, a, 1)	7m 10s
integration (ubuntu-latest, lts/*, b, 1)	8m 24s
integration (ubuntu-latest, 21.x, a)	7m 14s
integration (ubuntu-latest, 21.x, b)	8m 8s
integration (ubuntu-latest, 18.x, a)	7m 33s
integration (ubuntu-latest, 18.x, b)	8m 36s
integration (ubuntu-latest, 16.x, a)	8m 1s
integration (ubuntu-latest, 14.x, a)	8m 10s
integration (ubuntu-latest, 12.x, a)	7m 42s
	3h 40m 5s

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