BridgeJS: Support throws and async for closures #2716

Job	Run time
Test BridgeJS against Swift versions (swift:6.3, 603.0.0)	3m 10s
build-examples	57m 39s
prettier	15s
check-bridgejs-generated	3m 18s
format	39s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	21m 12s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	14m 43s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	13m 25s
Build for native target (macos-15, Xcode_26.0.1)	4m 7s
deploy-examples	0s
	1h 58m 28s

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