[embedded] Annotate test/Index/index_embedded.swift as REQUIRES: swift_feature_Embedded

Author: kubamracek

test/Index/index_embedded.swift

@@ -3,6 +3,7 @@
 // REQUIRES: OS=macosx
 // REQUIRES: embedded_stdlib
 // REQUIRES: swift_in_compiler
+// REQUIRES: swift_feature_Embedded
 
 struct SomeStruct {
   func simple(_ someClosure: () -> Void) { }