Embedded: Swift SDK now passes the `-Xcc -D__EMBEDDED_SWIFT__` #1599

Job	Run time
Build for native target (macos-15, Xcode_16.4)	35s
format	30s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.0.2-release/ubuntu2204/swift-6.0...	2m 48s
Build and Test (ubuntu-22.04, https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-R...	3m 3s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	3m 4s
build-examples	14m 3s
Build and Test (ubuntu-22.04, https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT...	3m 4s
deploy-examples	0s
	27m 7s

Provide feedback