Embedded: Swift SDK now passes the `-Xcc -D__EMBEDDED_SWIFT__` #1601

Job	Run time
Build for native target (macos-15, Xcode_16.4)	36s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	6m 21s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.0.2-release/ubuntu2204/swift-6.0...	4m 55s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	4m 55s
build-examples	12m 9s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	6m 10s
format	38s
deploy-examples	-1s
	35m 43s

Provide feedback