[embedded] Add test/embedded/availability-macos.swift

Author: kubamracek

test/embedded/availability-macos.swift

@@ -0,0 +1,13 @@
+// Checks that in Embedded Swift, we allow using stdlib types even when they
+// have declared availability to be higher than our macOS deployment target.
+
+// RUN: %target-typecheck-verify-swift -target arm64-apple-macos14 -enable-experimental-feature Embedded -enable-experimental-feature Span
+// RUN: %target-typecheck-verify-swift -target arm64-apple-macos15 -enable-experimental-feature Embedded -enable-experimental-feature Span
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: swift_feature_Embedded
+// REQUIRES: swift_feature_Span
+// REQUIRES: OS=macosx
+
+func f(_: Span<Int>) { } // Span is @available(SwiftStdlib 6.1, *)
+func g(_: Int128) { } // Int128 is @available(SwiftStdlib 6.0, *)