add guards support in JavascriptParser #6027

Job	Run time
validate-legacy-node	14s
unit	1m 4s
lint	1m 55s
basic	1m 23s
integration (ubuntu-latest, 10.x, a)	8m 26s
integration (ubuntu-latest, 10.x, b)	9m 4s
integration (ubuntu-latest, 20.x, a)	7m 2s
integration (ubuntu-latest, 20.x, b)	8m 14s
integration (windows-latest, 10.x, a)	12m 28s
integration (windows-latest, 10.x, b)	12m 9s
integration (windows-latest, 20.x, a)	10m 15s
integration (windows-latest, 20.x, b)	12m 4s
integration (macos-latest, 10.x, a)	18m 21s
integration (macos-latest, 10.x, b)	12m 51s
integration (macos-latest, 20.x, a)	11m 59s
integration (macos-latest, 20.x, b)	11m 5s
integration (ubuntu-latest, lts/*, a, 1)	7m 5s
integration (ubuntu-latest, lts/*, b, 1)	8m 16s
integration (ubuntu-latest, 21.x, a)	6m 52s
integration (ubuntu-latest, 21.x, b)	8m 8s
integration (ubuntu-latest, 18.x, a)	7m 39s
integration (ubuntu-latest, 18.x, b)	8m 29s
integration (ubuntu-latest, 16.x, a)	8m 14s
integration (ubuntu-latest, 14.x, a)	7m 57s
integration (ubuntu-latest, 12.x, a)	7m 43s
	3h 28m 57s

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