BridgeJS: Support throws and async for closures #2714

Job	Run time
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	6m 59s
Build for native target (macos-15, Xcode_26.0.1)	5m 26s
build-examples	6m 58s
Test BridgeJS against Swift versions (swift:6.3, 603.0.0)	2m 48s
prettier	12s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	7m 4s
check-bridgejs-generated	3m 29s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	6m 58s
format	35s
deploy-examples	1s
	40m 30s

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