Add opt-in tracing hooks for JS bridge #2010

Job	Run time
Build for native target (macos-15, Xcode_16.4)	4m 36s
build-examples	5m 50s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	1m 5s
check-bridgejs-generated	2m 59s
Build and Test (ubuntu-24.04, https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT...	1m 20s
Build and Test (ubuntu-24.04, https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DE...	1m 21s
format	35s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	1m 20s
deploy-examples	1s
	19m 7s

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